||I won't kid you, this is a top of the line gun.
My friend owns this gun and he never lets me borrow it any more because I sighted the Red Dot in to the hop up at around 225 feet and put over five rounds into his face in a single burst at about that distance. Accurate is an understatement and I was only using .2g bb's.
Extremely compact and is probably among the top 5 CQB AEGs you can buy, maybe even top 3 in my book. This gun is a little too small for my tastes really, but then again, it's so easy to use and so light, I can't really argue.
The magazines... hooooly crap, the standard mags look awesome and the hi-caps have an advantage that no other has that makes this gun just that much better than any other. When you run with an M4, G36, AK, etc hi-cap mag, you can always hear *ka-shush! ka-shush! ka-shush!* from the bbs going all over in the resivoir when you move, but with the P90, you can't hear anything because the way it's designed, the bb's are pushed towards the back by a spring powered wall and that keeps them together so it doesn't make a sound. Good for you, bad for the person you're sneaking up on!! :D
Bulpup design, awesome. Bulpup for those who don't know, is having the recieving chamber/magazine in the back of the gun allowing a longer barrel to be added on. This makes the P90 the most accurate SMG in Airsoft because it has the longest barrel. Make it a tight-bore barrel at 6.05mm and you will hold your own against full sized assault rifles.
The red-dot on the gun is awesome and saves a lot of money since you'll already have one. It's very accurate and is easy to sight in(usually it comes sighted in but I modified the hop up and had to readjust the sight to match it) It uses 2x AA batteries that fit right underneath it and are easy to replace if you need to(after a year my friend hasn't replaced his yet)
Really I only have two, one is the battery compartment. There is a tiny set of curved humps on the back that prevent you from being able to use a 9.6v battery. Fortunately they're just plastic and I had a dremmel on hand to show them who's boss. Now my friend uses a 9.6v in his gun and the ROF is just unfair....
The other I suppose isn't a con, but can be annoying, and that's the hi-cap mags. Partly why it's not a problem is because how well it performs, but the winding wheel is on the bottom of the mag, meaning once its on, it can't be accessed until you remove the entire thing. This really doesn't prove to be a problem though because Tokyo Marui made theirs so that when the mags are fully wound up, over 90% of the ammo can be fired in one huge Rambo-sized, no-reload spray so when you have to rewind it, you're out of ammo anyway and will have to reload.
Other than that, this honestly is a flawless gun even after over a year of use without maintinence. Barrel design, red dot, construction, performance. All of these are top quality and this gun is a perfect example of why Tokyo Marui is known for good guns. I have recommended this gun to more than one person and all that have bought it have thanked me later on because this is really a top performer and has met and exceeded all expectations for airsoft guns.
Rating: [5 of 5 Stars!]