Oh OK, what's up with it? I believe that getting an M4 platform would be the best to start with, and thought that this would be a good option for under £150. Do you know what a better option would be for under £150 in a CQB scenario?
Looking deeper, I've found this rifle; slightly cheaper but Valken rather than G&G: http://www.patrolbase.co.uk/airsoft-m4-m15-m16-variants/valken-battle-machine-cqb-railed-aeg-black.htm#.V12nIfkrKUk If not this may be better: http://www.patrolbase.co.uk/airsoft-m4-m15-m16-variants/combat-machine-cm16-raider---black.htm#.V12nTfkrKUk Both look good, but less keen on the sights for the G&G model. What would be the recommendation?
You'd likely be fine with either, however certainly for M4s in the under £150 range G&G have the reputation.