I am a big fan of the Penny Hardaway, Vince Carter and Deron Williams picks. Also Yao.
I have Penny and Deron as my third and fourth best PGs in this draft behind Kidd and Payton.
Penny's best AST% season was 32.2% (and that was his only season over 30 and had just 2 more over 28). Not exactly good for a PG (I mean Rose, who I've been getting a ton of crap for was at 38.7% his MVP season). And Penny, while he was a fairly decent steal generator, was a horrid defender overall. He doesn't make up for any of that by being an excellent outside shooter or rebounder either, and it isn't like he was going for 30 a night.
I'd take Rose over Penny any day of the week and twice in the playoffs.
I like Penny better because I think he is superior at creating high percentage shot attempts (whereas Rose takes a higher proportion of medium-to-good percentage shot attempts) + at 6-7, he creates a major matchup problem size wise, both of which enabled him to be a much more efficient scorer (TS% of around 60%) and also allowed him to be more consistent (tougher to shut down, like Rose was by LeBron).
I also like that Penny didn't need to dominate the ball as much as Rose to create those shot attempts which makes life easier on his teammates. Allows for more ball movement and involvement from his teammates. Overall, I think that makes him a considerably more effective offensive player.
In terms of defense, I'd give Rose the nod over Penny and give Penny the edge as a possession creator.
Anyway, that's why I rate Penny higher.