| Id skip on violin rosin. Ive used bernadel cello rosin, and currently using jade solo bass rosin. Bernadel is the hardest bass rosin Ive used and it works well. Maybe a bit too powdery for my liking, so now Im settled on jade. Jade is a tiny bit softer, and you can use less of it and rosin your bow less often, while still creating a lovely smooth tone.
These harder rosins give you a finer tone than any of the softer ones youve mentioned. Its best used with lighter guage easy to bow strings (spiro mittels were no trouble to bow with hard rosin), and yes I even count spiros in that category, hard rosin is a trick that helps to get a good arco tone out of spiros.
Hard rosin also excites higher harmonics within the string giving you a richer tone influenced by the character of your strings. On the other hand soft rosin muffles those frequencies and gives you a grippy orchestral sound.
When the bow sticks and slips, soft rosin gives the string heavy plucks, while hard rosin gives lots of little plucks. That weird explanation makes sense once you hear it for yourself.
Im not an orchestral guy, so Ive never been chasing sheer volume with heavy strings, but I do classical work duets trios etc, and Id recommend trying the harder rosin for that. Theyve always had plenty of grip.
Oh and, IMO the really soft ones like oak gum up the bow for good. If you want to use hard rosin, use it after a rehair and dont use any other rosin on the bow. I suppose if youre a classical guy youll want 2 bows in your arsenal eventually anyways. | 
