The only problem with it is that it is under GPLv2 only. This is because it was based on an earlier helicoper mod also under this licence. This means you can't use it within GPLv3 terms or anything looser than GPLv2 (Such as MIT).
Aside from that licencing issue, it's got great balancing, appearance, and all around quality. I highly reccomend using this mod wherever the licence doesn't prevent you.