Build quality - 5/5 - This new series of M4s is Tokyo Marui's first to feature metal bodies (with engraved Colt trademarks) and one-piece outer barrels. Everything is extremely solid where it should be, and there is no wobble to be found anywhere on it. The gun has a very nice weight to it, and is a huge step forward from Tokyo Marui's previous plastic-bodied M4s.
Internal quality - 5/5 - The SOCOM shoots at about 300 fps out of the box with .20g BBs. The rate of fire on a 9.6v battery is fairly impressive, and the gun shoots fairly accurately once the hop-up is properly configured. The recoil is rather impressive, and makes shooting the gun an absolute blast. It also makes the sound the gun makes when firing pretty fearsome, and can very easily strike fear into the hearts of your opponents.
Aftermarket accessory compatibility - 5/5 - On the first day I had the gun, I couldn't fit the 9.6v nunchuck battery into the handguards, so I went down to my local airsoft shop and purchased a set of Magpul MOE handguards. The SOCOM has a real-style delta ring, which allowed the MOE handguards to go on with zero modification. I also switched out the original stock and pistol grip for Magpul MOE replacements, which also went on without any modification. Next on my to-do list is a replacement front-sight and a tightbore barrel.
Functionality - 5/5 - The SOCOM and SOPMOD use a new magazine system (older M4 mags aren't compatible without an adapter) that makes the gun stop firing when it runs out of ammo. This forces the bolt-stop out, and it must be pressed back in when changing to a new magazine. High-caps are also available for the gun, but they lack the bolt-stop feature. You don't really need them anyway, considering that the low-caps are only $24 on WGC and hold an impressive 82 rounds. Once you've gotten used to the gun's bolt-stop feature, it's hard to really imagine ever going back to a normal AEG (I know that I can't!).