"Breathes very well compared to a full face mask (the range we have has a pretty basic but very protective paintball mask as the default, so it is what I compare the mask to the most.
Requires a bit of bending/adjustment to get it to fit your face if it is not exactly your face type (in my case I had to bend it downward as if squashing it a few times, and
then had to hammer out a few of the face creases.
To give scale for sizing.
31 year old male. 5'10 250lbs with a big ole head.
Weight: The mask was very lightweight, i'd say less than 2lbs. No discomfort over long periods of time. Almost like wearing nothing at all at most points (better than a full protective helmet anyway).
Adjustments: The entire back of the mask has a "flap" which can be velcro attached to the sides. Easy to adjust, once you get it just right, you can pretty much just pop it off and on at will with only minor ear discomfort. I tend to ride the mask a bit low (so you can basically see my entire face through the mask...not sure if this is correct, but is the best looking, most comfortable to wear, and most effective).
Bending Adjustments: The entire face-plate is a metal mesh...while it is difficult to bend with your fingers directly, using a non-edged tool and a flat surface will let you get the general shape you want. In my case, I actually had to first straighten out the face-plate (as it had a few creases), and then bend it downward, outward and then in to wrap around my face. It effectively made the front face-plate become more "flat" and it gave me the best adjustment to allow my nose, cheeks or mouth to NOT be squished in. I've got a round head with "chipmunk cheeks" (as my wife likes to call em), so there was a lot of mid and lower-face adjustment for me to do...once it was done the mask fits right every time I put it on. Be prepared to shape this thing a bit. When my wife put it on it looked huge...but bending it around her face actually made it very snug very quickly...so I'd say it'd fit a lot of different face types with no problem as long as you adjust the initial shape to your liking first. (She's got a tiny little head. It was almost adorable seeing just how much extra room was left when she tried it on after I adjusted it properly for myself the first time).
Ears, Nose, Cheeks, the whole shebang... it's basically like wearing a fencer's mask only with more metal on the sides for ear protection (and and two small openings in the rear on either side of the flap for ventilation and adjustments. Actually protected more than the paintball mask did on the rear (as the paintball mask just used a strap and side coverage.
If you are tagged on the top or sides of the "padded" parts, you can hear it (and feel the vibration with none of the bite). Easy to tell if you've been hit both audibly and by feel. The face-mask took several 30 to 20 foot hits from some pretty powerful GBB rapid fire rifles with zero issues (the same long burst which tagged the mask tracked down to my left arm and shoulder and I can't say I didn't feel THOSE...so yup pretty good at protection since my face was only contorted in the agony of a hit on my shoulder not from the face-mask hits).
Direct and even glancing hits were very audible from almost any distance, which is something I like as it can confirm a hit if either I or the target is wearing it (keeps everyone honest! i'm sure EVERYONE calls their hits...sure.)
The only huge negative I can give about the mask. The mask is made of mesh. the problem with mesh? Visibility. Anyone with meshed goggles or face-plates can tell you, your visibility will be cut down. i'd say if you can see clearly with a pair of goggles (if they're not fogging up on you of course), then cut that distance in half. you can now see shapes, colors and movement from a distance with no issue, BUT the clarity of the vision is gone. You can't see exact detail of anything around you, it's just going to be a mesh covered blur of some shapes here and there unless they're close up. (take an old styled baseball cap with mesh backing (trucker caps?) and flip it around to look through it...kind of like that, only a bit better at letting you see through it).
If you're used to aiming by tracking your BB's in mid-air for correction and adjustments the mask won't work for you because even SEEING your line of fire is next to impossible. If you have a personal rifle you're fine instinctively shooting with it should work GREAT! (I recently bought a G&G combat machine i've been sighting, and also reaction drilling with, once I was locked in on positioning and muscle memory, the mask worked fine for the purpose.
Using a rental rifle where I couldn't tell where it was shooting before I started using it was a different story, I couldn't tell if I was actually hitting far off targets unless the target called a hit or I started hearing/seeing pinging misses. A person can absolutely be VERY effective with the mask on, but it is a little frustrating not absolutely knowing if you pegged that hit dead on with only a shot or two because you can't see exactly where the shots are placing (just a personal qualm, so ignore if you're good enough to not worry about it, or simply don't care.)
I'm certain with an Aimpoint Red Dot or similar optic would work fine with the mask as the illuminated sight would be easy to pick out among the backdrop of whirling mesh, sweat and tears, but iron sights would only work if I could get the right angle between the mesh to line it up right (most people don't try to sight or aim accurately, so no biggie in quick paced moments and movement where accurate and precise fire is not a necessity).
Comfort: Plenty of padding inside (never felt the top of my head was going to be in pain or anything after wearing it for longer periods of time...after adjustment had nothing pressing on my face at all). Mask is pretty much fully adjustable. If it smooshes in your face, bend it. If it's too tight, re-adjust the velcro. Simple and effective, and can be re-bent/adjusted for different face sizes. Bonus.
Additionals/Externals: Velcro on the right, left and center of the "helmet" and also a large patch on the rear. I am certain they're made for various attachments, patches or signals which could be useful (or maybe even some sort of protective covering, or attachment system for a hard shell?)...probably would be useful if I can find some patches to label me as red or blue, or green/red etc for team games, as they would be easy to see and probably pretty darn useful.
Side Note: Field Specific issue
My indoor field requires FULL eye coverage and protection at all times by something rated ANSI z87.1. Now in theory mesh goggles and masks CAN get this rating (someone correct me if i'm incorrect in this) BUT our field requires you still wear eye protection along with a mesh mask. The thought of getting plastic shards in my eyes also makes me want to wear additional eye protection. My only issue? my eye protection (pair of wrap around shooting glasses I wore under the mesh mask) fogged up almost instantly on the day I played (granted it WAS a bit muggy and we were in an indoor/outdoor field in Florida, so environment may play a major factor). I'm thinking of purchasing a pair of goggles to wear OVER the mesh (something I think I've seen but have yet to find a correct product to fit my needs). I think the velcro on the sides of the mask could be used to secure the goggles onto the face-plate. I'm working on it and we'll see!
Overall, the mask did an excellent job protecting my face, but just be aware of the loss of visibility you'll get while wearing it. If you want to ensure you get crystal clear Eyeball MkI vision without fogging...you'd probably be better off sinking into a decent pair of no-fog goggles and a half-face mesh mask with a hat or head-wrap for upper-head protection. I'm going to hang onto this one and see what I can do about some externally mounted goggles. Great buy!