What do you think of them?
Happy to answer the question but just curious to know why you're asking about the UK specifically and why they should think any different to any other WP users out there?
I've been on board since the original concept of WP7 was revealed back in February 2010. I've currently got an HTX 8X and it's been a love-hate relationship. I love WP and everything about the OS. I love the look and feel of my HTX 8X and the slim and sleek design is a winner. It has a few quirks and the camera's not a par with Nokia's offerings, battery performance is average but since I charge my phone every night, it's never an issue.
I do not have anything good to say about HTC's support of WP thus far. They've poured all their resources into Android. They launch great WP products at the outset and then ditch them from the day of your purchase. They've added zero value to their WP handsets and that has hurt over time. I will never get another HTC again - my next phone is likely to be a Lumia 930 or 1520 if I can get one on my network - Nokia care about your purchase and continue to add excellent value.
Well I've got on great with Windows Phone on the whole. Started with a Lumia 800 and then went to the 920 which I'm currently using now. The only thing that annoys me from time to time is the app situation. Even in the UK where apparently WP is at 10% (you would never guess that looking at what people own, mostly Samsung and Apple from what I see), many UK companies still choose to only develop Android and iOS apps. Hopefully this improves as time goes on.
A lad I play football with whipped out his phone last night, saw it was a Nokia lumia. Asked him what model and he said "Its a 520, its ****" I am the only person I know with a windows phone who actually likes it. No idea why no one else seems to.