I never have to restart the app...you should not need that either in
development mode. Maybe your config is wrong, but Compass should setup
this by default. Sass::Plugin.options[:always_check] should be set to
true. Run the script/console to check the value in runtime. (Dunno
about Spree default Compass settings though, I just started with a
Spree sandbox)
If you still wanna go CSS - me myself rather die =) - it should work
to delete the sass files and create css-files in the public
stylesheets folder.
grimen