I'm with plan9 here.
Let me weigh in on the Ubuntu Tablet UI (Firefox OS seems to be very similar to the iOS pattern, so not too much need to discuss). Making the vid, pics, people, and apps as separate screens isn't good for a universally usable UI. The screens for each are basically pre-made and unchangeable widget screens like android already has (except the Android screens can be changed to suit the user's individual or businesses preferences and needs). Most users probably don't want a compete screen (that must be swiped to/from) dedicated to music; they just want to set up their playlist and then have quick access to play/pause, next/prev, and volume. The only dedicated screens that I've ever thought were effective (and then mostly for phones) were the apps, multitasking, and feeds screens from SwipeUI.
A specifically mystifying thing is the People view as all your messages must be accessed SEPARATELY through the pulldown menu.
A personal gripe is that the app view has an available for download section at the bottom. There is NO REASON for me to have purchase suggestions on my home screen. If I'm interested I'll go to the App Store and look at recommendations there. This same problem extends to videos and music sections. I understand the need to get sales, but hardwiring this in isn't the way.
The dock gesture is horrid for real usage. The edge swipe isn't the problem. The problem is that the user must not only keep their finger on the screen while sliding up and down (a serious usability problem in landscape mode let alone if portrait mode is needed). In addition, the element being selected is obscured completely if the right hand is used and the tablet is awkward to press if it is being held by the right edge and constant pressure is being applied to the left side by the left hand. If a thumb is used, then the entire left hand must be slid up and down the side of the tablet. While a small swipe can reveal the menu for clicking, the use of both paradigms for the same function is somewhat confusing for new users.
To get to the app view from an application, the user must drag across the screen. So, we have thumb gesture to switch between applications in the dock only to realize that the application (for whatever reason) isn't there. Now another gesture is required (and a complete repositioning of the hand) to swipe across the screen to switch to app view. On a phone, swiping most of the way across the screen (remember it's only a couple of inches) takes you to app view while a complete swipe opens an app from the dock. The difference is subtle enough to create some frustration and (to new users) a UI where gestures sometimes change at random.
I love the theory behind the pulldown options and then drag left/right to get to the one you want, but I think dedicated tabs are a must as the current pulldown requires complete visual and manual focus. Accidentally pushing or pulling just a little before releasing is going to happen (especially when a little distracted) and trying again isn't such a great idea. Dropping down a series of tabs across the top of the screen wouldn't affect the current flow in any way, but would add great accessibility, and easier switching between options (the current method is to pull the menu partway up so you can then move right or left to change menus).
I also like the edge swipe up to reveal menu options, but then the tablet UI puts the options on the left (presumably to not conflict with the phone apps running on the right). On touchscreens, the top of the screen is the most fatiguing part to interact with and (for the majority who are right handed) the upper right is not only the most fatiguing, but also blocks visual access to the remainder of the screen. So, let's say that you're using their photo-editing application. First you swipe up (probably with your right hand) to reveal the menu. Next you move to the upper right side of the screen and click the menu to access (for example) contrast settings. Next you have the choice of adjusting the settings with your right hand and repeatedly moving it out of the way to see the picture or you adjust the settings with your left hand and give up some manual dexterity and comfort. While I'm ambidexterous (favoring my left hand for most high-manual-dexterity tasks), I know that most people aren't and this will be an annoyance (whether conscious or not).
Gesture overloading is a BAD idea. Swipe from left partway to open app dock. Swipe completely to go to app view (only when in an App); however, you have to swipe from right to left (the opposite direction) to go back to the app, but the same swipe brings up side view apps when in an app. This gets even more fun when you realize that doing the same left to right swipe in an app with a side view open doesn't close the app (this takes a short swipe from left to right), but instead switches between open side view apps without giving you a preview. However on the phone (since it only runs phone apps), the right to left swipe always switches all open apps.
The use of edge to edge, edge to near-edge, near-edge to edge, and near-edge to near-edge (and all of the left-to-right and right-to-left combinations) for critical functions is too many functions with gestures that are too similar.
While I see the individual apps getting better (and I like what I see some of them), I don't see the fundamentals of the OS getting better and that makes me thing that Ubuntu OS isn't the OS for me. I think that Gnome-shell UI would be much more consistent and easy to use in a tablet and could be adapted to phone devices (though I'm not a fan of it on my desktop as I feel it's too restrictive compared to KDE). With some work, I think that the KDE netbook UI could also work well as a tablet UI (most of the the fundamentals would transfer well, but better touch integration is necessary) though I think Plasma Active is fairly good (but the developers seem to be getting lost in the semantic desktop, automated suggestions, and activities instead of focusing more on the fundamentals of UI).
Edited by hajile - 3/4/13 at 7:15pm