In reply to Jon Stewart:
Firstly I have to say grading boulder problems is harder than trad as you grade for a nominal easiest sequence, generally more affected by morphology. I always knew when something was too easy for its grade but sometimes had missed a trick when something felt too hard. You need a good team at the grade.
On the data, the Cool Running pair are about the same grade in all the major current guidebooks (once you take into account BMC V3 is Rockfax V4. Cool Runnings is given f6B+ in the VP and Rockfax guidebooks
On V grades its a classic 'victim' of the fact that once Rockfax defined V3 as f6A its a real problem that other guidebooks will have V4 to f6B+
Next, it's not the only guidebook bouldering 'bumbly' grade table issue, Peak Bouldering also have UK tech grades a bit too low for 6a and 6b. The YMC grit guides have my favourite grade table with the fewest annoying factors in my range (mostly sub UK 6b).
Finally although I've not done either problem and had no input to Burb infinity boulder grades I have watched quite a few climbers on them. From that I suspect the BMC grades probably should both have been V4 6b: In Font terms from the VG guide, CR as given f6B+ and CRLH a f6B seemed OKish at the time but that perhaps exaggerated the difference. However what do I know, as all six UKC logs give mid f6B for CR and all 12 logs for CRLH as high F6B+ !?
Coda...not been to those problems for 10 years. I've been told popularity and traffic has made things harder across Rivelin.