Chinese smartphones - user experiences?

[MikeLowry]

Hi everyone, my trusty Sony Z1 appears to be on it's deathbed after a hard three years of use, and so I am on the hunt for a replacement. I have been lusting after a Sony Z5 Premium for a long time but haven't been able to justify the expense to myself.

I've recently become aware of Chinese smartphones seemingly offering significant bang-for-buck, I've read lots of reviews online for various phones (didn't realise there were so many !) but am keen to hear real user experiences. What Chinese phones are you guys using, and what are the pros and cons? I am after a decent all-rounder, speed is important to me over most things (laggy phones irritate the life out of me) so decent processor speed and/or RAM? I don' think I would want to spend more that £150 if buying one of these phones. Someone on another thread recommended a UMI Super which appears to be decent.

As an aside, any Z5 Premium users care to offer their experiences? Initial reports seemed a bit iffy, how are people getting on a year after the launch?

Thanks!