After getting some advice on here I decided I couldnt choose between the fire xc pro and the highroller xc, so I bought one of each and put the XC on the front, HR on the rear. Not got a problem with its grip,seemed pretty damn good on anything but as soon as the way got rocky I snake-bit the tube (at about 40psi), the 2 or 3 wheel rotations between initial blow-out and stopping saw 4 further snakebites and after 10 patches (never use Bell patches) it failed miserably and I had to drop in a new tube borrowed from a mate. Pumped it up as hard as I could (guessing around 55-60psi) and set off, reduced grip but within 200 yards I got a smidge of air (6 inches) and landed on some slightly rough stuff and bang - another snakebite and a furthe 3 snakebites in the time it took to stop. Ended up having to pootle round the rest of the course ignoring anything vaguely like air and cringing over rocky sections. Very unimpressed with it.
The XC pro seems flawless but as yet has only been tried on the front so not subject to the same trials, but it doesnt feel like it has paper sidewalls like the HR.
Maybe its a candidate for tubeless? Maybe I should just sell it to a skinnier rider?
On the positive side, the fire XC pro seems perfect, endless grip in just about any condition, rails round corners like its on err rails, perfect sidewall stiffness. So thanks to those who advised me on that one!