At least it's a non-essential internal part and not something like the hop window in a barrel, or the gas valve port on a magazine, since I sold my Gen2 M16A3 I've had nothing but positive experiences with WE.
The comments I got from Iain at Milspec about GBBRs were quite enlightening. Mainly that with the newer WE guns, people usually only have problems if they half upgrade with RA-tech parts. Fully stock are fine, fully RA-tech are better, but mixed tends to cause problems.
I think my next gun will definitely be a GBBR of some description or another, I'm just torn between an L85 and an M4 CQB... Not that I'll be able to afford either for a very long time.