I operate at lower grades (at least for leading), but would say the grades at FCQ do feel pretty inconsistent. Dunno why, perhaps not enough ascents?
For instance, Truffle felt like it could be a contender for the softest HS in the region if not the country - more like V Diff than HS. I kept putting in gear (there's plenty), expecting a hard (for me) move, which never materialised. The voting on this particular route seems baffling and I often feel UKC voting is unhelpful for determining grades - lots of confirmation bias? Reading lots of comments about overgrading/udergrading is a lot more helpful than the voting, as you know thought has gone into writing rather than just a lazy confirmatory box tick... Meanwhile, there are neighbouring routes such as The Bristolian Affair and Halfway to Kansas which feel round about correctly graded, perhaps a little upper end.
Also, The Socialist seemed pretty soft for Severe 4a, good gear most of the way and nothing terribly technical, felt V Diff.
Then go across to The Glacis and pretty much all the routes here feel hard for the grade. For example, Pueblo, graded V Diff feels like 4a climbing without particularly frequent gear.
Of course, grades are always a bit subjective and often you can find yourself struggling or finding life easy at a particular location, but does seem to me at FCQ, the grades are a bit all over the place.
Post edited at 17:22