Re:
So today was a bit of a shoot out. I thought that the Explosif and the Hot would have similar character, and that there wouldn't be too much difference, other than in stiffness (Ultrastrong tubing) but out I was wrong.
Despite the Hot having the all steel Horse Shoe brake-booster, it is still considerably lighter and feels a different animal. Acceleration is faster, more zippier, and racier in a straight-line but the Explosif is a more comfortable ride. The Hot is like on 'roids! The RM-400 Pro rims are nice. Geometrywise, the Hot seems also to have a long top tube (I will have to measure to compare)
I'm not a fan of the XC Pro shifters, I prefer the robustness of XTs, so will be swapping them out at the next opportunity. The classic combination of Kool stop brake pads (fitted today) with Dia Compe 987, and Ritchey Levers is definitely more effective than the XT brakeset and has more modulation.
I will have to get the purple old faithful Explosif a bit lighter, starting with the Bottom Bracket, fresh rims, and a new set of cranks.