My team and I have done some tests on are side also.
We tested with a 390 fps M4. The results gave us some concern but interesting discussion about energy transfer vs fps came from it.
I would think that playing with this type of ammo could be good for 350 fps sniping or 300 fps AEG or 250 hand guns considering the transfer of energy.
Playing with this type of ammo could bring lower fps and "maybe" more safety to the game. But more testing would be need to confirm my theory. Would people be willing to loose range for accuracy? The concept of not seeing your bullet when you shoot is more milsim spirit?
I'm not looking to change anything but just take a minute and think what changes could be done for a more positive playing experience with this new type of ammo.
Then again sometimes change is not good...
~~~Honor The Game(tm)~~~