Aptana does have intellisense like behavior plus all sorts of other things for SVN, CSS, XHTML, etc. etc. It has tools for simplifying all the rails generators and starting up a webBrick or Mongrel development server is as simple as clicking a button. I haven't found it to be buggy and Aptana Studio Community is a no-charge product. I really don't see how you can go wrong to at least give it a try. They have some good video tutorials as well.
Good luck in your search.
ya try net beans... its good but 1 thing i can suggest you... if you use IDE, everything is like spoon feeding and u may not be able to learn ror... try and learn ror.. after some time, shift to IDE...
I 'd vote for aptana as a plugin on eclipse, this gives the flexibility of eclipse and the benefits of radrails. I had problems using apatana and then loading plugins (editors and designers) on top.
The only OS worth working on... OS X :) And the only Editor.... TextMate :)
I am very biased.
Yes Aptana has some refactoring. This link talks a bit about it and points to the current list. http://www.infoq.com/news/2007/11/aptana-studio-10 Aptana also releases updates frequently, constantly adding features or bug fixes. I'm very happy with this IDE.
Dontcha love being a fan boy :)