XC and Mono are the same except eh XC has a disc mount, both with 21 engagements 3 springs all at once nothing offset. Bulb has 36 engagement points and I think it too uses 3 springs however its ratchet teeth are a lot skinnier as it fits all 36 into one ring, thus they break a lot for trials. Ti Glide is old as far as I remember, again its a mono with a Ti main body with out alu flanges, 21 engagements, 3 springs nothing offset. I would reccomend spending a bit more, as most people probaboly will and getting the Pro II trials hub, 48 engagements, 4 springs, offset 2 engage at a time on a 24 tooth ratchet, thus lots of engagements and very strong as the teeth and ratchets are deep.