Might be hot for indoor fields
Vertical foregrips interfere with folding stock
Lightweight (some may like it, others may prefer something heavier)
Loud (sound may scare the hell out of your opponents, but that's not so good for stealth)
All in all, the pros outweigh the cons. This is likely to be the best GBB I've ever bought.
Rating: [5 of 5 Stars!]