Have been playing with all 3 of these wordpress themes, and this site currently is built using Thesis. I have recently been building and transforming all of my client builds over to Genesis, and am loving it.
I recently purchased the developer license for Headway, which, don’t get me wrong, is a really cool piece of kit, but I find it really isn’t as good as the Genesis Framework, I just find the customisation alot easier to deal with in Genesis, I am not sure wether it is because I am used to using Hooks on Thesis, so the jump was quite simple in that regard.
Genesis developer license gets you a bunch of themes, future upgrades and some cool plugins, as well as a helpful community to bounce ideas from.
Headway looks great for a blogger wanting some quick and easy custom features, but you can easily get lured into purchasing extras, which I think is where it gets unstuck, you don’t want to pay for a premium theme, only to dish out extra money on features that should come with it out of the box.
So, for now I am about to change this blog over to the Genesis Framework, and give Thesis a rest, and forget about Headway, unless I need a quick and dirty blog.
What do you use?