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.
"SEO Friendly" is so vague and so overused. I just checked a site from the portfolio of a theme which claims to have the "best SEO ever" and there's no canonical link in the head section and neither admin nor RSS links are nofollowed. The Home link is nofollowed but there's no replacement for that in the footer (which may have been forgotten by this theme user, but I disagree with that "Nofollow Home and put a dofollowed home link with useful anchor text into footer" technique anyway, because I consider it dangerous to nofollow the own Home link, because even with the dofollowed alternative in the footer, the nofollowed link is still there. There are better ways to achieve the desired result - avoiding a "Home" link anchor text on every page - like using a Home graphic with keywords in the ALT text, or Javascript.)
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.