Those are the two major differences in the amps specs. And yes I know they aren't major. But you know what else bothers me about this? The rubi is more aesthetically pleasing. I think it's a better looking amp in general. And plus, you may think 20 watts difference won't matter, but it does. A few extra watts per speaker (within rated, no clipping) is a good thing, who wouldn't want that.
Edit: THD Picasso - .03
THD rubi - .015
Again, tiny ass difference but a difference nonetheless
you wont here that difference in power, and they way you said it in the first post was the sales guy was saying the Picasso had a smaller THD.