As I get more and more into samplers, I'm able to write some reviews and observations. I've been able to demo/try vsampler3, exs24mkii, kontakt and ds-404. I won't compare them, but these are the ones that I've looked at.
The DS-404 at first seemed cumbersome with the function button thingy. After using it a bit though, I find that it is very functional and fast. Absolutely no complaints there. I'm also happy with the amount of information that is available on the front panel. My one complaint is that I run my screen at 1400x1024, and at this resolution the graphics get extremely hard to look at. I'm almost unable to read the white text on the panel (the text on the display reads fine). I think this is becoming an issue with most vsti, as people use finer resolution screens.
The sound seems very good to me. Definitely nice filters. Support is excellent, and the product is very stable. I'm not sure about cpu use, I haven't noticed this as being high (or low for that matter).
In conclusion, for basic to moderate sampling I can't imagine a better product. It doesn't mangle you sounds in the same way that kontakt would or exs24mkii would, but that's a whole other ballgame in terms of price and intended use.