I love CSSEdit so much that I was wanting Espresso (that is, CSSEdit for HTML) even before I knew it existed. I'd tried Coda, but it just didn't feel "right" to me.
Having tried Espresso as a demo on the day it was released, I agree that it doesn't feel quite as all-inclusive as CSSEdit--the lack of an X-ray equivalent feature is odd, and there are a few other things I was expecting that aren't there.
That said, it still does almost everything I want from an HTML editor when used in conjunction with CSSEdit, so I was still almost certain I was going to buy it anyway at the upgrade price (from CSSEdit). I of course jumped on the MacHeist deal with the assumption that it's dirt cheap for the time being, and if v2 eventually fills it out I won't feel the least bit bad about paying full price then.
For $40, I'd go for it. Surely a few of the other apps will give you some use (Library 2 yay!), and I think it's certainly worth that much even with the few weaknesses.