Is the Sony Xperia U worth it at all?

[Dialaphone]

Hello

This is a good question I hope I can help you make your decision with a few points to consider.

The Sony Xperia U has a 3.5" touchscreen which is powered by Sony’s Mobile Bravia technology, The Xperia U is also quite light as it only weighs 110g. In terms of internal technology and with regards to your given specifications, the Xperia U has a 1GHz Dual Core processor. A full suite of Google apps are also included in this handset so Maps, Gmail and Youtube are there for you right out of the box. A 5mp camera only adds to this very capable handset. Take a look at the link below to see a few more details together with some great customer reviews.
http://www.dialaphone.co.uk/phone/Sony_Xperia_U/

Finally you mention the Nokia Lumia 800, this handset is playing a big part in the success of the new Nokia Lumia smartphone range. It's got a stylish design, 3.7" AMOLED screen that is slightly larger than that on the iPhone 4S. It also has a powerful 8MP camera, 16GB internal memory plus 25GB Sky Drive and facebook photo album sync so you should really never run out of storage space.
Some other cool features are it runs on the new Windows 7.5 Operating System, comes with Internet Explorer 9 for fast browsing, and also has an exclusive ESPN sports App. Take a look at the link below to view a few more details and some customer reviews.
http://www.dialaphone.co.uk/phone/Nokia_Lumia_800/

I hope this helps you make your decision, good luck.