Ask HN: A better setup for local Rails dev (Vagrant?)

I've been trying really hard to use Vagrant for local development with Rails (3.2) to avoid configuration/dependency hell amongst the team and our various setups. For configuration management, it's great. But loading a page in the Rails app from the host machine is just too damn slow...it takes anywhere from 5 to 10+ seconds to refresh the page. And this was after disabling reverse DNS lookups in WEBrick and using the rails-dev-tweaks gem. Setting config.assets.debug to false helped, but that sucks for JS dev. So, what are any of you guys doing to avoid painfully slow load times or config nightmares in your Rails shops? FWIW we're using Ubuntu (precise32) and serving with Thin hasn't helped either.