
I'm using a virtual operator and I was happy with my country variant firmware (Spain/operator ONO/carrier Movistar) but... BE CAREFUL!!! If you upgrade to Windows 8.1 the roaming issues will return and it will be necessary to reconfigure your settings to allow the phone to connect to the network in roaming mode...
Very bad work, Microsoft... why you have updated the roaming configuration file? People having Lumias will not be able to modify manually this file and will need to wait again to our corresponding country variant firmware. buuuuh!
(By the way: somebody has solved these problemns with the roaming? Is it possible to modify the XML containing the roaming information for virtual carriers?)