Well, unfortunately I didn't get to see Leandrinho at all this season. Actually, he played only 10 games before he left to US.
But I watched many games the season before, when his team (Bauru Tilibra) won the Brazilian League. He was the ROY, and averaged something like 15 points and 5 assists a game. He wasn't the first option (actually he was the third option) on that team, as he was still very young.
This season though, he was on his way to be the MVP. He was the second leading scorer (only behind Oscar Schmidt) and among the league leaders in assists and steals.
About the comparisons, it's really hard to compare his game to any player. His game is kind of unique. He's ultra fast, VERY good going to the basket, and is a good shooter despite his shooting mechanics.
Sometimes he looks a little bit out of control with the ball, since his ballhandling is as unique as his shooting mechanics.
He definitely plays taller than 6'3, and I think he could play some SG, (although I don't think it will be necessary, as the Suns already have Penny, JJ and Casey to play the 2). But from what I've seen of him, he's a POINT guard, definitely. He likes to pass, to involve his teammates.
The good thing about him is that he loves to run, so I think he'll fit perfectly into the Suns system.