I purchased this m4 as a Christmas gift (Dec 2011) for a 12year old player's first airsoft experience... Let me put it simply: its built like a frickin' rock. Great build qual. and new-user friendly. Using the included battery, this thing has an impressive ROF and is superbly accurate up to 150ft and so-so out to 180ft, with .20 bioval bbs. At that range its accurate enough for him to take me with a headshot pretty easy ...traded rifles back and forth with family for an afternoon and this was the favorite hands down among the guys that had never played airsoft before. The stock wobbles a tad but holds position with authority. No other rattles(other than sling mounts).
very accurate with quality ammo
built to last (at least externally, too new to say on internals)
heavy solid parts all around, balanced like its real counterparts
included 8.4/1100 battery performs quite well
actual chrono: 385fps w/ .20g
adjustable stock holds where you set it
mag feeds reliably with a shot of silicone
manual is entertaining... an infant on a shooting spree as the safety warning? really?
a bit heavy for kids
hop-up didn't seem to do anything, but i may need to open it up to have a look inside
"manual" is sad: this is a barrel. this is a stock. don't look down barrel when you pull the trigger, etc.