Should the designs work in gmail, in my tests the font size, headings and colour are not respected - should they be?
The templates were designed to give you solid results across all the major email clients. Having said that, Gmail (and others like Outlook 2007) offer very little CSS support. To get your email looking pixel perfect in these environments means going down the inline CSS route with every single element inn your email. For example, you'll need to set the font, color and size for every paragraph individually with some inline CSS like <p style="font-family:...;color:...;font-size:...;">
We tried to keep a balance between something that looked good and was still easy to update and tweak yourself.