Broughton grades

Yesterday I managed to escape work relatively on time, and as GCW and Nik were on duty and I was on the clock I decided to head over to Broughton.
Unsurprisingly there was noone there, as is so often the case, but this is sure to change when the clocks go back. It's usually quite busy by mid-winter. I didn't really warm up, as everyone knows warming up is for gays, so I jumped straight on to a 5c. Normally at any other wall, or outside on a 5+ or 5c (which roughly equate to the same thing) I would probably flash it, or get it done on the second or third go.

Not at Broughton.

This got me thinking about grades, and place, and I wondered whether it was for the fact that I'm less used to this style of climbing (overhanging, crimpy in nature, limestoney). I can discount this based on the fact that overhanging crimpy style climbing is pretty much all I've been doing lately. In addition to this I'm definitely feeling stronger because of it.
I couldn't really put it down to the way I was feeling, because for once I was actually quite psyched to be crimping down, I'd eaten well so had plenty of energy and being a Monday I wasn't too tired from work.
The only thing I can put it down to is the fact that the grading is particularly harsh at this wall. It's not helped by the old school English grading (well, it was built in the 80s, so is excusable).
The real question being: is this a good thing or a bad thing?
For me, it depends greatly on whether you're chasing numbers or not. Grades are always subjective to the place, and relative, so if I was expecting to crush English 6b at Broughton (Font 6b+/6c - V4/5) as I would expect to at, say West View, I'd be very disappointed.
In the event, I managed to struggle up a 5c+, and I've never been up a 6a in all the times I've climbed at Broughton in the last 5 years.
But this still begs the question: what is the true grading? It's probably easier to knot fog than find that answer out.