"Hey is this phone running Android?"
"No it Tizen"
After 60 seconds of looking at it they both admitted that the thing I was moaning about was horrible but that it wasn't something they had to deal with on their Galaxy S3s. When they showed me the S3 it's mechanism was definitely more intuitive (at least to the three of us).
While I'm not defending the skinning efforts of OEMs generally, I don't think the historical position of "it's all awful" is necessarily true any more. Sure there are bad things in there but there were plenty of bad things in early versions of Android. Just as Google learned there are signs that the OEMs are learning too.
Having said that I've got a fairly close to vanilla Jelly Bean on my SGSII now and I can't think of anything I miss from stock.
The main problem is that for such minor enhancements, you are condemn to be always late in android updates.
We are now fairly aware that updates are not only about getting new features and bugfixes, but also are the main mean to avoid security breaches.
If OEMs don't get that, what to expect if they build their own OS ? Not saying it will be bad, but they'll have hard time to alleviate my worries about that.
Not anymore, anyway. But TouchWiz added quite a bit before ICS came out. Off the top of my head: a customisable dock bar, resizable widgets, a paginated app menu, the app switcher you get when holding 'home', power saving toggles in the notifications drop down...
Admittedly these days it's just a way for Samsung to put a unified, iPhone-like interface across all of its phones, but in the beginning it added a number of features missing from Android.
This is probably kind of subjective, but my problem with TouchWiz is it's butt-ugly. I mean, if you think stock Android was a mess (and it's not so bad now with Holo) then TouchWiz is to stock Android as a 2 year old's art project is to the Mona Lisa.
It's a horrible mess of Holo, Gingerbread and just weird random stuff that doesn't fit with either.
I find Android UI even though not consistent but still much better than TouchWiz
Tizen doesn't have to wonder much, they can go and add the features shown to be liked by people. They can get "inspired" by both iPhone and Android.