I was tearing my hair out this weekend to find a usable html/css editor. I was so disappointed with every tool I used; they were all terrible for what I wanted to do: quickly iterate design ideas for layout and content.
After talking to Annie I figured out why this is. Nobody actually uses html editors in this way, to do first-pass design. That's what photoshop is for. I've been driving backwards. Once I sat down and started sketching out my interfaces in flash (where I'm comfortable drawing boxes, etc.) I started making real progress towards my actual design goals.
When I got the thing looking pretty good in flash, it was actually pretty easy to translate it into html/css using any reasonably competent html editor. The one I'll probably stick with is the one that's included in Microsoft Visual Web Developer Express, since that's where I'm working on the nuts and bolts of the site itself.
In conclusion, every html editor sucks, but they suck less if you know exactly what you want to build before you sit down to wrangle divs.