+1 I used this jetpack in my old community and it performed the exact same with 10 players all the way to 70 players, very consistent. We could also do formations in mid air like firing lines, single columns, wedges, etc. and it added a new layer to rping that was a pleasant change from the norm like having your battalion set up behind some windows on a big building waiting to ambush while the other battalion members were inside that building trying to get the hostage.
The only disadvantages that I can think of off the top of my head that can all be edited out through it's lua file are..
1. You can drop the jetpack through the c menu and another player could pick it up
2. There is this weird buzz lightyear model to the jetpack
3.(?) There is unlimited fuel
On my old server these 3 points were all edited out through the lua file so we could drop the jetpack and it simply vanished from the world, we made the lua file load a very small piece of wood from hl2 that stayed hidden inside the playermodel so we didn't have to look at the weird jetpack model it has, and we could only fly for like 15 seconds until the invisible fuel bar ran out and you had to lay off using the jetpack in order for it to refuel
This jetpack is fucking awesome