I also have problems with the wifi randomly dropping the connection (says limited connectivity) you have to forget the connection and then make it again to get it back. This is very frustrating. Other wifi devices in the same room as the 15z have no problems at all.
I have had the 15z for almost two months, and the connectivity problem exists as well, on virtually any network that I use - random disconnects that are only remedied by hibernating/restarting the computer. It is very annoying!
Inspiring. Ultrabooks have found their way into Dell's Inspiron family. The all-rounders of the past now benefit from lower weight and longer battery life, in addition to the good performance. We examine whether the ultrabook measures up to the broad multimedia class.