GitHub User: antonbaron
+1 for the OpenStruct. It really makes it rails way. I used to add value: hash['field'] to each dynamic field and that was evil ;)
There's also a little gotcha to even more decrease feedback time: just try add :bundler => false to both rspec-guard and spork-guard configurations in Guardfile and if you can run these commands directly (not through bundler), you'll see that total run time will be almost equal to testing time.
That's so because by default guard runs all commands through "bundle exec" which takes some time to initialize.