I'm aiming for something with Panel that may not be interesting to dedicated users of MC.
In that case I'll relay my wife's experience of using Panel:
1. Finds it difficult to access (has to remember an obscure ip address and port number based on whether she is at home or work to connect, unless she remembers to make several mobile bookmarks, which she never does).
2. Doesn't understand what the icons mean (need labels)
3. Will never touch the settings page to play with audio conversion settings, cue next week: "honey, why is my phone bill so high?" (basing conversion quality on wi-fi vs mobile network access would be a nice start)
4. "Where are my playlists again?"
5. "Why is it so slow?"
6. "When are you going to figure out how to make more Radio buttons?"
She didn't mind the colors though, so maybe my initial negative impression of the design was off.
I think some of those things are better handled by an app but not necessarily deal-breakers. She can still access our media library if she really wants to (but not as often as she might if she were using a dedicated app). That said, she's very familiar with Theater View because she has been using that on our HTPC for years. That level of familiarity available on a mobile device would be very successful with non-power users that already have an MC-aficionado in-house, although I'm not certain that it would be so beneficial for brand new users.
For additional reference, she's also familiar with listening to music and podcasts in apps such as Rocket Player and Pocket Casts, as do most of her friends.
Back to our combined perspectives, I think it would be best to have a native Android app that looked like either traditional android players (for brand-new users) or Theater View (for users familiar with HTPC's running MC). It would also benefit the pocketbooks of users if the solution could easily toggle between a remote and local library, in addition to scaling conversion settings on-the-fly (based on a cellular or wi-fi connection). I see Gizmo as being much closer to those solutions than Panel, currently.
Anecdotally, it appears that currently, I prefer the web-based option more than my wife. Which indicates that maybe it should become a remote graphical portal for power users with something nerdy like clickable MCWS actions
Edit: And one more thing she just found difficult, easily switching between Panel and other apps or browser tabs on her smartphone, especially after entering full-screen view.