Here's a quick video I recorded earlier, demonstrating the new Walkman NWZ-A840 series's UI. The UI is heavily borrowed from the touchscreen based X-series DAP, features a couple of downgrades when compared to the basic looking but highly intuitive one found previously on the A810, S630, S730 and others.
The previous 'now playing' shortcut that can be toggled anywhere within the system by pressing the 'Options' button has been replaced by 'to playback' shortcut that isn't available everywhere, but a whole a bit more useful than the previous incarnation as it presents more shortcuts depending on where in the system you are on. Tracks can also be added to a 'wishlist', which is useful for people with a subscription based music service. For people who likes to purchase CDs (like me), the feature is kinda redundant, but it is there for those who wishes to use it.
The system as a whole felt slightly slower, but I didn't find this a major issue for day to day usage. We are also still cursed with only two custom EQ slots, and the lack of quick find (the table with alphabets is missing) is also irritating, particularly if one is planning on installing hundreds of albums. On the other hand fans of podcasts (fancy word for pre-recorded radio) will be happy that the A840 supports them out of the box.
You can't create, edit or delete playlists on the device itself (it must be done on a PC, which isn't really difficult). This is something that irritates many, but to me isn't a huge deal as I don't tend to use playlists a lot. But what I do wish is for Sony to bring back SenseMe, the auto-playlist generator that I loved on the S630/S730. It was a brilliant piece of application.
So one step forward, but two steps backwards. Not good Sony.