I've had this unit for a few years, I had originally bought it as an analog front end for an M-Audio Delta 1010, but recently started using the ADAT in/out with my Focusrite Saffire Pro 40. Here's my impressions:
Compared with the preamps on the Focusrite, I'd say these are in the same territory, though maybe a bit more sterile sounding. They seem unexcting, and don't seem to flatter much. I get my best out of them by not running them too hot, and on signals that aren't begging for mojo. Don't run the pres too hot -- they get noisy on the last couple gain settings.
Compared to my GAP Pre-73 or BLA B12A, they seem very boring. I can get much more fun and mix-ready tracks out of those pres for most things. But, I've still never had any issue getting useable and useful tracks out of them. I typically reserve them for my additional drum tracks and they do fine in that purpose for the price.
The conversion quality seems respectable for the price at this level. Again, on par with the Focusrite interface, and useable. Next to my nice conversion, it is lacking on low and high end. So I would much prefer the nice stuff on the main money tracks in a mix, but for the extra tracks, it works fine in the mix.
Also, the insert jacks are a nice touch for outboard.
Overall a decent expansion box for a modest setup if you need more tracks of utility to add to an ADAT in. With the prices these go for used, you could add 8 i/o to yor setup rather cheaply these days.