Those two utilize the Parent-Child theme mechanism of Wordpress (I think), unlike Themeframe which creates standalone Wordpress themes.
The code is similar to http://wordpress.org/extend/themes/atahualpa
What a theme can do SEO wise (which is only so much, it cannot create inbound links for you), ThemeFrame will do.
The code is light and even more importantly it is very, very robust.
If I were to buy a theme or framework I'd see how well it works in IE6. And if you want to create fluid width themes, whether it can do that (without dropping the right sidebar in IE6, if there's oversized, non-wrappable content like images or space-less strings in any column). Checking for these two things will make your shortlist very short indeed.