I have an XA like the second one you mentioned with the conical expander bolt. I've yet to encounter an XA with the wedge style, though I'm betting it's an older version. Personally, with the minimal differences that are visable once installed, I'd go with the lighter conical exander XA. Word of warning though, that rubber insert is a major pain to remove and an even bigger one to put back in - just in case you get any ideas about that. When I bought mine - it had a yellow insert in it, and the seller included a white one. Well my bike was blue and white so logically I went to replace it. 45mins later I finally got the job done with some sore fingers and a broken mini-screwdriver.