- load problems on mobile (pages were sometimes entirely inaccessible)
- lack of control- for example, no way to use Disqus as the default discussion forum
Given these issues, I basically went back to Blogger's default templates. But just because you use a default template doesn't mean it has to be boring! I start with a default template (my current favorite is the picture window because it allows nice tabs at the top for pages) and then use advanced template options to modify the background image, layout, size, colors, etc.
I also usually enable a mobile template to make it easier for mobile users to browse posts. Btw, by default, Blogger's mobile template has uses Blogger's defaults; if you made modifications to your template and want your mobile site to look like your modifications, select "Custom" when you're enabling mobile site.