I've tried all three (granted the Ubuntu versions were via VirtualBox with XP as a host, but I gave the images all the available RAM my system has). Loading the rails environment is taking 30-60 seconds. rails console, rake test:units - anything that requires rails to load up. And not just on the first go - every time. I've even used autotest to see if it helps with execution time for unit tests, but it doesn't. Any time I change one test, it still takes 30 seconds to load them, and then about 4 seconds to execute.
Has anyone else come across this issue? Has anyone figured out any way to fix this?