I'm impressed.  Nothing against Subtext, but I wasn't extremely pleased with it.  The code felt very asp.net 1.1 to me. 

Here's why I switched:

• Creating a new theme in Subtext seemed like a royal pain.  Each new theme needed new user controls created all over again.  It didn't take advantage of Master pages either, which is why it felt 1.1 to me.
• BE.NET was built recently and therefore has the things in mind a blog should in the year 2007.  Little things like a text box for pasting in Google Analytics tracking code and customizable entries for pinging services.
• Subtext required SQL Server to run as the datasource.  BE.NET by default saves everything as Xml.  It has a SQL Provider, but it doesn't look complete yet.

I lost some settings in the process of switching blogging software though:

• The import tool with BlogEngine.Net got the articles and contents, but lost names of the commenters.
• URL's are formatted differently.  Google will have to reindex.  If this was a popular blog, I'd worry about it.  Since I've been neglecting this blog for a while and only have a handful of articles, I'm not going to sweat it.
• Looks like the comment spam protection with BE.NET is lacking.  I'm sure this feature will arrive soon.