There definately are issues with iWeb sites.
Regarding iWeb, I can only say, that I am not sadisfied with the pages, it produces.
I have since the beginning problems with my blog, that can not be sorted out (failure messages at the end + missing dates).
A lot of things on my site, that do look normal in Safari look obscure in other browsers (textboxes are not transparent anymore, galleries don't show up).
On top of that, all sites load awfully slow.
I look now for a solution for these issues. Rapidweaver is maybe an option. I will have a look into it.