That doesn't surprise me. The VFC has great externals but I've heard some absolute horror stories about the gearboxes (mostly from 'mericans though so.... ).
Mine's a G&G and it's bloody lovely. Bastard heavy with the EGLM on it though.
The elusive BTC, I nearly purchased one myself but they sold out before I had the chance. I would like to try it. The Mall is good, and I should get over to Ironsight one day.