On the Bravia Internet link, it's a bit clumsy to get things set up, since there's a few different ways to go. Once you find the activation/referral code, though, it goes pretty smoothly. On the other hand, after the commercial break, it ends up replaying the last few seconds of video from before the commercial. Also, the user interface pops up at every segment transition, which is just annoying.
The other obnoxious thing is that in the "group by shows" view, it shows episodes in most-recent-first, and doesn't show anything about which episodes have been watched, or any sort of episode number, air date, or the like, so it's hard to tell which episode is next. Presumably this isn't an issue on the queue view, but presumably that also means having to go through my entire queue just to see the most recent few things.
The PS3 interface is generally better (of course I'm a bit biased), but also requires having my PS3 (with its noisy fan) running. It isn't too bad, though, but it's still a bunch of extra stuff to have to do to watch. But at least the public version supports the various BD Remote keys (I can thank myself for that!), and the show view does a much better job of organizing the content. It would be nice if there were a group-queue-by-shows view, though, and not just for subscriptions.
Image quality seems a bit better on the PS3 side, too. It's probably getting the same data, but the PS3 is playing it back through a video library that provides excellent upscaling, while on the TV it seems to just be doing a naive nearest-neighbor filter.
The thing that still kills it for me, though, is that most of the stuff in my queue still isn't available for Plus, and I have such a backlog of older things that I don't think I actually care about seeing recent episodes of shows when they're new. And of course all of it shows up on Netflix pretty much right at the end of the season.