Well one thing to say is that, I'm really glad I bought this, even though I still had a TM MP5A4 this just out does my TM. It's built very well, no creaks of any sort. For the most part it's metal except for the selector plate and grip as that is a very sturdy plastic, the handguard and stock butt plate is a strong rubber material. Another great thing is it has all reinforced/metal internals. Also, it has a good weight to it.
Not entirely sure but about of the box it shoots about 315-340 or so but yeah not too sure since I don't have a chronograph. This gun can probably handle a 9.6V battery as well. Also, it comes with 2 hi caps (metal btw) and a bottle of bb's. Another cool feature is that it has trade marks from the Special Weapons company. ICS has done a damn good job making a quality MP5. Oh yeah, it's not too loud like previous versions of ICS turbo motors.
The battery is also pretty easy to install you just pull out the front guard by pulling out two pins and connect the battery, then put the hand guard back on and you're good to go :D.
Metal internals/reinforced gearbox
2 HI-Capacity Magazines (a little over 200 rounds each)
Great feel to it
Good CQB FPS and RoF
Easy to Adjust Hop up
A little bit of stock wobble, but that seems inevitable
I guess it having to use a Small Battery could be a con but that shouldn't hold you back