My experience with 2.0.....I caveat this highly with the fact that I've had about 10 mins to mess around with it whilst my puppy kept jumping up and down on my laptop...
I have a Mk1 rack and player, I upgrade the player only to 14 and kept the rack at 13, so there is a direct comparison.
I loaded a few 2.0 profiles and they sound great...but....back to back with my rack, very similar sound and I'm not feeling or hearing much difference.
Couple of points that could explain this:
1) I didn't do a true A/B test as I was using different profiles and a slightly different set up for each ( different power amps).
2) As mentioned I didn't spend a long time on this
3) I'm a fairly clumsy player, not listening for dynamics etc so I might not be picking up the nuances
I nearly didn't post this because I don't think its helpful and I'm certainly not concluding that 2.0 is not worth it.
I'm also not bothered about "proving any difference", but my observations are that I can hear a minor difference, mainly around clarity. The Peavey 6505 Dill rigs sound really good BTW!
It also did remind me what a fantastic starting point we already have.
Another point to mention, as I've had previously, when I upgraded, few settings seemed to shift? Now this could have been me trying to load some rigs I built on my rack into a Level 1 player, which does throw some things, so I'm unsure if this is correct. The settings are reverb and delay where the mix seemed very high. The cause could also be legacy effects...