I used an x1.1 for a few months and it was OK. Grooming was nothing special, you get used to holding the handle when using the tools, but it worked fine, was light and no frills.
Not sure I'd sink proper dollar into one, and if I suddenly did I'd hunt out an SM1 with manual height control (which was the best bit about my sm2, but it was too large for domestic use!). But their main USP is if you want a machine to be battered about by people who don't give a shit whilst cleaning offices, shops etc, you go for a Sebo (or henry, but it's brushroll vs no brushroll that argument!)
I'm in a Sebo mood today, with my X4 and I might have inquired about a cheap X1.1 just now too...