Well lets just look at his frame for one. He is 6'5" 194, and is 23. Much taller then Wells and he is somewhat skinny at the moment. Right now cause of his light frame he is mostly a line drive hitter that has some pop. Though most scouts seem to think once he puts on some pounds and gets stronger he could develope into a Juan Gonzalez player. It seems that Juan was also very skinny in his younger years and many see some of Juan in Rios at his young age. That's his potential though, not what type of player he is right now. If you want a good comparison of who he is right now, I would say look at a Baldelli type player. Both are quite young and have the frames to get a lot stronger. Right now they are line drive hitters that will show occasional pop, though Rocco is ahead of Rios as he does have more experience in the bigs. Rocco being 6'4" 187 and Rios is 6'5" 194 like I said before. Rios also has very good speed, not as fast as Baldelli, but very good speed. Most likely won't show it off much in Toronto as they hardly ever steal bases a lot.
So Rios and Wells really aren't close to being the same type of player. I'm guessing some people compared the two because both played CF, have good speed, and Rios looks to be really good in the future (obviously Wells obviously is already). But when you actually compare the two, they don't have much in common.