My Comments.
I'll be working on a dark theme as this one fullfills my moderate goal for a light theme.
I don't like there being two profiles, one for site, one for forums, however, it's a necessary evil. DotNetNuke has its own forums, but they are not mature in development. If DNN 6 has the good forums integrated in its released, we'll look into converting the YAF forums into the DNN flavor. I doubt that will happen since the YAF forums are one of the best out there and their support is really good.
I do not like the new post icon behavior. If you click the forum category and click each thread, the icon works as expected. If you access the forum category via the quick link or the little icon's to the right of the last post user name, they do not behave properly. This is supposed to be fixed, or is fixable. I've seen it on other YAF forums that work as expected.
The forums signature box is not positioned level with the user information box. I don't like that.
<-- was just told I'm not the first to bemoan about this and it's fixed in the next release 1.9.5.6When making/editing a post, sometimes you lose everything. I've started copying everything I post just in case, lol.
I like the flow of the site and how it's structured,
the admin panel is fantastic,
I really like both the thumb up/down feature and the Thank feature,
the banning of users is really nice you can even suspend someone for X hours or from a specific forum,
its written in a language I'm familiar with (C# and ASP),
installing modules/extensions/skins is extremely easy.
Overall, the site is really great and with having the source code and it being in a language I'm knowledgeable leaves expandability virtually limitless. I just need to get familiar with the nuts and bolts of everything and then I can start tinkering.
I'll probably start working on a dark theme this weekend, or the next.