I've seen Rigo train in Miami and yo...dude is small. I've never seen Nonito in person but I know come fight night he's going to be a lot bigger than Rigo. Skill wise I think Rigo has more technique, but against Donaire at the level he's at right now I don't think it's going to affect him. I also don't think Rigo's punches will have an effect. We've seen Rigo stunned several times, but if (and when) he feels Donaire's power...it's a completely different league.
If I'm a Donaire fan though, I'd be a lil concerned that maybe Donaire doesn't get up for this fight and takes Rigo for granted (which I think is what many of the Rigo fans are hoping for). I like Rigo too, but I think Donaire is at a different level right now.