That would be kind of like the upstart competing against the veterans!

I haven't tried any of the others apart from Atahualpa, though I have been tempted by Thesis. The thing is, I have never tried drawing comparisons between my work on WP and someone else's, because of two main reasons:
- An analysis by me where I am one of the competitors will see shades, if not broad strokes of subjectivity
- Given that Suffusion is a fairly new entrant (the first release with an Options page debuted in late August), lot of the features on my theme are things that have been implemented by the ones you have listed. And some of the other themes have a lot more to offer. In fact I drew inspiration from a lot of the themes out there (and I am sure most theme developers do the same). As you have said:
marcnyc wrote: it will push you to add the features other themes might already have and suffusion might not YET have
I do this today on a case-by-case basis, though I implement things my own way. E.g. I scoured the internet for slider-related stuff and found that I could use JQuery Cycle very well with my range of options, so I used it (discarding my previous choice of s3Slider). Other themes had implemented sliders long back, but had probably used some other mechanism.
Somehow it would feel weird to actually list out a table drawing comparisons, when I am trying to play catch-up. E.g. A lot of themes offer "magazine modes", which I plan to do, but I have been getting sidetracked.
I would be happy to include someone else's analysis in this aspect, though, even if it were damning of Suffusion.
Cheers,
Sayontan.