I'm confident that the preamps should be excellent, I remember being quite sceptical when reading Robin Bigwood's review of the R16 where he put the preamps in the same ballpark as the Dav BG1 but it wasn't hyperballs (I have a BG1), they are supremely clean and detailed.
Including the low end?
The conversion is on a par with good hi- mid level interfaces, no audible difference to me with my Fireface 800. Totally usable in most if not any real world scenarios.
I would personally go for the basic model, leaving control surface duties to a dedicated control surface.
Is this not what sold SSL into a market leader though?
I think Mr Stranks might be quite a smart little cookie...