I've upgraded many parts on my 05 Rockhopper, but havn't changed the cranks. I've been watching ebay, considering which cranks to buy when I picked up an older Trek MTB that just had a new set of Shimano Deore Hollowtech cranks installed. I know these aren't XT cranks, but are they enough of an upgrade that I should make the swap or is this basically an even swap and not worth the effort. BTW, both use a square taper BB. The Truvativ is 172.5mm and the Shimano is 170mm.