I think that maybe 3 or 4 models on the POD are really good sounding, and none of those are from the 2.0 upgrade. Being able to access cabinets using the effects knob is cute but doesn't really do anything for me.
I *think* that the tuner got a little better, and maybe switching models was a little faster, but I don't do much of that either.
I got mine for like 45 bucks...which should be the going rate. It's kind of worth it to upgrade just because you can.
As posted, the main advantage is to get at the cabinet simulations on board (vs. through MIDI). I also think the tuner is better - but I don't depend on the POD tuner - so this is mute.
That's it. Also 2.0 allows you to change the ranges and settings for the FX by using the Tap Tempo method as well. That way you are not stuck with one Delay time with X amount of reverb. You can fiddle with the parameters a bit more withouth MIDI.