Usually we like Walkman phones, but the W350a was an exception. Its flimsy design, unintuitive controls, and mediocre camera were distracting and the handset had middling call quality as well. It's not completely hopeless--music quality through headphones was satisfactory and the feature set is decent--but it's not our choice for a Walkman phone.
If you're an AT&T customer with a penchant for a Sony Ericsson Walkman phone, we'd suggest the W580i instead. The W350a is currently free with service, and it comes in three colors: ice blue, electric black, and white.