Bought a Lumia 520 last month.
Overall it is a very nice device for a good price.
My experience with the Windows Phone 8 OS is a mixed bag.
It looks nice, but after some weeks of use I'm still not sure that the typographic "metro" UI is an improvement over the more traditional buttons and icons.
The application-selection is limited and a lot of developers clearly still need to get a hang writing metro style interfaces (even within Microsoft). Some applications are just terribly confusing, others work remarkably fast and intuitive.
For example the touchdevelop app from Microsoft research is confusing and the (later pulled) Microsoft Youtube application is really good.
Since Microsoft is betting so big on modern/metro UI, they really need to do a much better job in convincing people these typographic interfaces are an improvement.
I was also surprised that the user interface actually is often rather different from Windows 8. It looks similar, but Windows 8 uses swipes and gestures much more than Windows Phone 8 does.

I also experienced a fair amount of bugs. So I would advise people to wait for the Amber update that is planned for next month. I experienced problems registering my microsoft account and the application update feature in the store seems to be broken, also had some crashes and reboots.
I will reserve my judgement to see if WP8 can become my primary phone OS until that update. For now I'm glad I didn't buy a more expensive WP.
In my opinion 160 euro is a good price to test WP, and you really should try WP before you switch!