No offence Limun because this is only my opinion.
This is why I didn't bother with Grunge because there are too many cells, too many borders and too many rounded corners and the whole thing looks like borders and border-radius gone mad.
I was going to have a look at it with the "Pro" theme because I think that has less cells stacked together. ?
Don't know, but the picture gives some sort of idea that I had in mind. But that's a lot of work to re-write most of the cell classes and add extra ones. Probably too much unless you can make something stunning and not something as drab as frozen phoenix.
The other thing of course is consideration for how the theme comes up with mods and plugin's - or just let them worry about it - That's what I would do, otherwise one's creativity is being stifled by what others want you to do. And I for one don't see that as helping anyone who finds making themes a pleasurable pastime, rather than it turning out to be a pain in the proverbial butt.
Still OT:
One would have to wonder how much work Yros would have to do to make that theme look anything decent for the "Older" browser's - - -
Probably wouldn't even think about trying it.