If I had the money, I would get the Jackass, I regret buying the Xtra stand. Just a few days ago, I took off the right side wideloader to more easily cruise our city trails and I remember why I don't take it off usually. It is a stupid design, I don't know what the folks at Xtracycle were smoking but it was some bad stuff on that day. I never compare the cost of an attachment like a kickstand to the cost of the bike, I compare the cost to the usefullness of the product. If I needed really nice shifters on a crappy bike then I would get them, knowing I could transfer them to a better bike later.
Other than the terrible design of the kickstand, I do love the stability of the bike though I did add another piece to widen the kickstand on the side I load heavier pipe on. Did I mention how hard it is to deploy if I am using both sides of wideloaders? I had to add a piece to the front so I could catch the kickstand with my foot because I can't reach it with the wideloaders on.