Yeah, but in the MTB world, "slack" is pretty slow handling compared to say the average "Gravel" bike. It is an enhancement if doing big drops with fast run-outs. But often considered somewhat of drawback if doing quick flowing technical trails. An advantage in rough stuff (does not get knocked off line easily), but is not considered "quick" or "lively" ...

I think dropping by a LBS and taking one for a ride would answer all your questions. Since I'm rarely over 25 MPH on dirt, I do not like slow handling. If it was like when I rode off-road motorcycles (a lot), I was a neutral guy. Only in desert bikes, where 100 mph was possible, was I looking for "slack"