It's my first proper Android phone, and I was immediately more receptive of using it in comparison to other Android phone I had tried - especially various Samsungs. This is mostly due to the MiUI Android fork used by Xiaomi. The interface is sleek, and very iOS like. That said, there are still a lot of small interface issues that I just haven't managed to figure out - like can I get rid of the Google search bar on the main screen or at least reduce the estate.
My other major gripe relates to the level of Google integration- my contacts are annoyingly integrated so searching for a name to call brings up email addresses and I keep getting notification updates on gmail when I have read emails on my iPhone (or desktop). The contacts part can be suppressed but doesn't seem to be permanent - every time I update or some other random even seems to switch it back to integrated mode.
I use the phone as my work phone, so I have had really good usage. Most of my blog posts in Hong Kong were done on the phone, and the photos were superb. I haven't had issues with memory limitations, but then I do use a limited set of apps, and clear my memory often of unused apps. I have had some occasional issue with volume (both microphone and speaker) but it seems to be difficult to work putt a pattern.
Overall, I am very happy - although I would probably just get another iPhone as a work phone in the future. Xiaomi just launched phones in South Africa, and it is definitely a good alternative to other Android phones. If I were to get another Android phone, it would definitely be a Xiaomi.