I'm one of the people who think the Xena is a great thing to have on the X1000, but they're not a "killer feature" unless/until someone comes up with some cool projects for it. You can buy XCore USB kits for ~$100 I think.

It's great to have it on there as an extra "bonus", because it's cheap (maybe $10 of the cost of the machine) and something different, but that's what it is.