I'm in LGW F lounge on average 6-7 times a month, sometimes more, it does the job nicely for me..

Quiet, decent fizz.. the three (trivial) gripes i'd have are:

1. Lack of seating during busy times
2. The volume and agressiveness of the air cond at the far end
3. Lack of the choice of mags/papers available in J lounge next door

All in a rather better experience than the screaming kids that often reside in the J lounge