hi Justin, you're doing an awesome job here and bringing WP design to a whole new level. Right now I'm testing out Ian's Thematic, using Tarski on some recent projects ( http://ladamedragon.com/blog/ ) and just downloaded Hybrid late last night.
I was getting the reload problem as well when adding widgets but waited for your answer to davek. Re "The secondary widgets can be moved down with CSS to create footer widgets. They can also make for a double sidebar. Or..."...
I guess it depends on who you ask, from a graphic designer's point of view, I prefer a clean, solid foundation with easy to manipulate options. So far Tarski & Thematic looked like my best choices for future designs(child themes) but I really like what I see in Hybrid as well. I understand some bugs have to be ironed out so I'm looking at it more from an ease of use/design point of view.
Re "Ian Stewart has a movable widget section on the home page. A user can decide if it goes on top, after a specific post, or at the bottom"... So far I found this widget layout option to be my favorite just because it's quick & easy to set up but I also like the flexibility of being able to move your secondary widgets around with CSS.
Re "Making a very basic theme is a lot harder than making a complicated theme"... I can imagine and as I said, you're doing an awesome thing here and a lot of people will benefit from these rock solid designs. I'm seeing projects like Hybrid & Thematic sort of like the next generation of Sandbox. Since I just installed Hybrid to take a look at it live, I haven't had time to play much with it but I'll post more feedback later. Thx Justin!