If you are a power user stock Android is the natural choice. I can see people with less demanding needs liking the fact that the skins have widgets and apps pre_installed but no experienced user would use any manufacturer app.
Paranoid Android is way better than stock anyway. Why don't Samsung look at what the deva are doing and give us features people would actually use.
And all the TouchWiz S4s can be fixed by flashing the AOSP ROM.
I choose stock Android because I don't want a load of extra stuff I didn't ask for installed. I don't flash ROMs on my Nexus 4, I just want to have my choice of apps rather than Samsung or HTC. To be honest there are some Google apps I'd never use that are built in and ideally I'd like to be able to remove those as well!
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I think it was more a retorical question
which is entirely the point, you make it look how you want it to look and not how the manufacturer thinks you want it to look