Actually, I believe it gives a dirty sound when used improperly.
If you're choosy with sample rate and levels it does sound really grimy and amazing for boom bap drums. You need to play back what you sample often when you first start and find what works for you. I find sampling kicks at lower sample rates hitting it hard is best, but hats need to be sampled at higher rates or they no longer sound like hats. But I almost always hit it 'in the red' (in the grey?).

Typically what I do, is sample from record clean into the 2000xl, since chopping and trimming is much easier and faster on that, and then record the samples into the s950 adjusting sample rate/levels from there. I like it better because I can then adjust the rate/level differently for kick/snare/hat/etc.

I love the ASR but if you already have another clean-ish sampler I wouldn't go for one yet. Although the ASR and 2000XL do have a slight character they add, both of them are probably close enough to the original source not to be noticed in a mix. I just love the ASR for making instruments out of bits of samples, because it's just so easy for that, and workflow wise the unit is really great for it (and some of the auto looping features work really well too). Also the ASR effects are killer - which is why I have a DP2 and a DP4+ (also I believe you can pass audio through and use it as an effect unit, if you have any use for that). I usually choose between the 2000xl and ASR for what I'm trying to do - not how they sound. The s950 pretty much only gets turned on for dirty drums or 808s.

Just realize when buying any of these units they'll all have a bit of a learning curve, but once you get over it they (mostly) make sense. IMO the s950 has nothing in common with the mpcs. And the ASR may have been the most difficult sampler for me to get into.