I have one, and since I am writing what looks to me right now to be the 8th post here, 12.5% of posters have a Xiaomi!
On the more serious side, I ordered mine (I live in the UK) from a Chinese seller who has a warehouse in the EU, and I know a few other people who ordered the same way (whether they are in UK, Greece, Netherlands etc).
Specifically, I bought the Mi4 a year ago for a little over $200, i.e. less than half the cost of other flagship phones with comparable (or sometimes less) specs. Naturally, it came full of bloatware/spywhere, on a Xiaomi you can actually open a browser, download a clean image from the manufacturer website, restart and have it clean-install just like that, not even need of a PC. Oh, and it has dual-boot, keeping a "clean" OS version in case you run into trouble.
Overall it blows away my previous Samsung (which still cost more than the Xiaomi last year, even second hand!!) in every aspect, including - believe it or not - manufacturer support, since you have immediate access to each (of the frequent) new version of the OS for what it seems like at least some years after release of a Xiaomi phone. It is an amazing value and I don't think I'll ever spend much more than $200 on a phone again...
Caveat: Chinese resellers will install spyware (not only on Xiaomi), so clean install once you get a phone!