Just to let you know I also just bought this here in China for use in CHina with China Mobile 4G, but its not working on 4G. just getting HSPA network. Despite what Xiaomi says on their website: http://www.mi.com/hongmi2/specs/#wire quite annoying to be honest. Not sure if it was going to work elsewhere on 4G, but Xiaomi is not very transparent with network information, and the multitude of bands available for 4G/LTE doesnt help much of course!
BTW, mine came with MIUI 7, when bought on the 15th of Oct 2015