There's one other thing that keeps it from being "really appealing", that's the fact that it doesn't tether well.
For fashion/editorial work it's not a deal breaker, but it would be nice to have. So, if they could fix that I don't see anything holding it back from the professional market (advertising, editorial market).
My S2 tethers fine. We're in prelight this week and set up the S2 and our Contax p30+, the S2 using leica image shuttle to lightroom, the P30+ using C1 V6.
The phase is slightly faster to view an image, especially on the first image, but after that they seem pretty even, though I'm not that concerned that a billion images come up on screen as we work.
I'm actually not concerned about shooting a billion images for this project, because we've been down that crunch road of quantity and it is not a money saving, or inspiring way to work and takes a lot of post work to fix issues that should have been attended to on set.
We also did the end of the world test, where you shoot, pull the cord, or the battery, intentionally mess things up and then see how long it takes to get up and running.
The S2 was easy, it picked back up and we kept shooting, so I don't see any issues so far. I'll know more in a few days.
I can tell you that there is a different look with the S2 my phase backs compared to my Canons. DXO is about numbers, maybe they're right or wrong, I personally don't care because in real world work I've seen much different results from scientific testing to the way I work in the world.
They trashed the Lecia m8 and mine shoots beautifully and the file is unique, but maybe that's just the way I work though I'm use to actually lighting an image and working around the "limitations" of file or camera and turning those limitations into a positive.
In fact that's what makes photography different than what we see with our eye, is the limitations of the "film", the lenses, the shooting rate and our personal style. A lot of time the equipment we use has a lot to do with our personal style and obviously scientific testing won't take that into account.
In regards to a cmos S series or any camera, I'm good as long as it's pretty, but not good if it looks generic. This is all personal preference, but the only cmos look I've ever liked was the original 1ds, the RED 1 and the olympus em-5, though I haven't used every camera ever made.