Personally, I don't give a flying duck about the shape of an icon or where the caption is, as long as it is consistent within the UI. Wikiwide's idea about the circle around the icon to give some additional info sounds good (one obvious example might be that the app is running, for apps that do not allow multiple instances, i.e. pretty much all of them). OTOH, I do take an issue with the widgets. I like the widgets on my N900 screen and miss them dearly on the N9 and Jolla. What I do not like is the widgets being random size. They should be exactly an integer multiple of the icon size plus icon spacing, otherwise you end up wasting screen space.

Examples of a nearly perfect UI:

• Hildon

Examples of less fortunate UI choices (with reasons why):

• Harmattan. No widgets. Unnecessary and therefore wasteful lock screen. When I turn my screen on, I want to see instantly what's going on, not to have to swipe to another screen first.
• Sailfish. Much as I like the OS, it unfortunately took some design decisions that moved the Harmattan shortcomings to the next level. The swipe approach makes it all too easy to do the wrong thing (send an email instead of deleting it, to name but one). Inconsistent icon shapes look messy. Days of the week in the calendar are hidden unless you swipe the screen down (exposing yourself to accidentally activating a menu option). That despite the fact that the bottom half of the screen is empty, so there is plenty of room for the header with days of the week. There is no general header with the current time, battery and connection status, quite crucial pieces of information in a phone. You have to change the screen to get that. Last but no least, whose clever idea was it to separate the apps' settings from the apps themselves?
• Android. Where do I start? No quick way of closing an application. No multitasking. Confusing configuration (Sailfish took some inspiration there). Admittedly I have not used Android for so long that I cannot give you more specific examples but I know I abandoned it mostly because I found the UI absolutely atrocious.

In many cases I see the UI (and UX) being a victory of form over substance. As if the companies employed a lot of graphic designers and suddenly ran out of things for them to do, so they let them loose with no regard to practicality. The Windows 8 UI is a prime example. So is Unity and Gnome 3. In all three cases, what these interfaces replaced was miles better than the brave new things, but a change for the sake of the change won.