Price reduction: Good time to upgrade from GNex to Nexus 4?

I've had my Galaxy Nexus for 1 year and 5 months now. Since I got the JellyBean update , the phone has been laggy, slow response times in many areas, it would freeze every now and then some features don't work properly anymore, like the music control widget on the lockscreen (seen only when playing music). It's because of this and other issues like battery life, that I want to switch phones. I initially did think about switching to iPhone, but I love Android so much that I cant. I feel like I would be taking a step backwards with the iPhone, even with the upcoming iOS7 additions. So, as a lover of stock android, the only option for me in the UK is the Nexus 4. The Samsung S4 and HTC One Google Play Edition phones will not be released in Europe. Neither will the Moto X. Besides, the price of these phones puts me off. With regards to the rumoured, Nexus 5, well there have't been any substantial rumours. Besides, whatever it is my worry is that Google may not release it in Europe, just like with the phones mentioned above, in addition to other devices like Chromecast.

So for those with the Nexus 4, what has been your experience so far? A lot of people say its great. But specifically, how does it fair , in terms of performance? Any lag at all? Any freezing? How is browsing? Some people have had issues with the glass back breaking. Any other physical hardware issues? And generally, considering the price reduction, would you recommend me going for it?