What I know about Arkansas stones is mostly from David Weaver. He would buy tons of stones and write at length about them on various forums. He also had some good youtube videos I'd point you to but he has taken all of them down it seems. Anyways, his advice from 8-10 years ago was that Dan's was best for a new hard/translucent stone (finer, more consistent), but that their soft arkansas was a little slow/fine-cutting for what he wanted a soft ark to be (medium/middle stone). He was recommending Natural Whetstone instead, since it was a little more aggressive, and cheaper.

I took his advice and got an 8x3 soft ark from NW that I really like, and a Dan's 8x2 translucent that is also great. I've never owned any other arkansas stones so I can't say much beyond that.