Had one for a few weeks trying to see if I can get on with Android after 5 years or so with iPhones.
If you get on with Android (ie had Android phones in the past) then the Nexus 4 is the best phone for the money you can get that is a fact.
I returned back to my iPhone because I couldnt get along with Android but also because the Nexus 4 despite is greatness it is not as well built as the iPhone 5 and chances are that the HTC One will be much better than the Nexus 4 as well.
The phone is very slippery and feels big. Near the top of the screen the glass with a bit of pressure caves in a bit, despite its processor the version of Chrome was very jumpy (might have been sorted with the new version of Chrome). The screen was nice but not as nice as the iPhone though in my opinion better than the S3. To me it generally felt a bit cheap on the hand.
Having said that if I liked Android and couldn’t afford the HTC One, I’d get a 16GB Nexus 4 without a doubt.