Passing on knowledge about software development and other related technologies.
First let me note that I am in no way associated with JetBrains (the developers of RubyMine), just a loyal customer. As a long time developer on many platforms I have always thought Visual Studio was the most mature and well thought out IDE (Integrated development Environment) out "in the wild". Many products have tried to copy it's success across many different platforms but none has impressed me as much as RubyMine has since I started writing Ruby and Rails applications.
What makes RubyMine so special? Well lots of things, but most of all it helps you to be PRODUCTIVE. Let me type that word again, PRODUCTIVE. Every aspect of it does what it can to streamline and help your code get up and running FAST. From automatically downloading new Gem's you specify in your project to checking code in and out of source control (several types are supported).
All the tools you need are there for testing, re-factoring, IRB, Rails console, database tools, built in terminal, and a VERY slick integrated debugger. Everything is tightly integrated and very well thought out. I have never been one to suffer ancient tools like Vim for the sake of being "king of the obscure". I enjoy programming but it is also my job to write code not tie my fingers in knots trying to remember obscure key combinations. So if you feel this way to you will most likely enjoy the added productivity of RubyMine.
JetBrains has a 30 day trial but once you start using it the cost is minimal compared to the productivity you will experience using it. I think you will be presently surprised.