Depends on which fans. Most of the fans wanting the Cinderella fantasy, where Veronica is pretty enough and "good enough" to change some rich guy into Prince Charming won't be happy with Leo. He is who he is. I think like Wallace there are no layers, he is what you see onscreen.

Leo does hit the good spots: 1. Older but not too older, allowing Veronica more sophisticated moments than high school hijinks, and precluding an explicitly sexual relationship (turn-off, too "real"). 2. Respects Veronica for who she is, and is impressed with her right away. 3. Forgives her using him, and will help her even with some risk. 4. Is cool himself, saved her Dad's life and plays in a band. 5. Signifies Veronica's outsider status, she dates someone from outside the school. 6. Her Dad approves of him (why not he saved his life).

Logan or Duncan, either one makes Veronica once again past the gate into 09'er dom, Veronica just isn't that girl. She never will be. Again, Duncan spent a whole year ignoring her, and Logan mocking her, and Veronica doesn't forgive. The mocking/ignoring was all for stuff she had nothing to do with anyway, so she shouldn't and that was I think a deliberate writer's choice by Rob.

I'd be sorry to see Leo leave, he does fulfill the nice boyfriend bit and is sweet.