I have been using Linux as a desktop since 1998. I can vouch for how ideal Linux is for RoR dev. It’s a natural home for it. I have done loads of RoR projects on Linux, obviously.
I don’t have a popular view. I think that an IDE is essential to RoR work (or any development). Proper debugging is always required. I spent an awful lot of time researching IDEs and by far the best was Netbeans, but unfortunately they have dropped support for Ruby in the latest versions!
I haven’t really found a good replacement IDE. On Linux, vim is ruby-aware. However, debugging and profiling aren’t a luxury, they’re essential and using text editors just doesn’t hack it.
My own preference will be to consolidate on Eclipse as it’s pretty much the swiss army knife of IDEs and if, like me, you are multilingual, its’ your common denominator especially if you combine Rails and Java (GWT anyone?).
The problems that you are having with battery life sound very much like it’s either your battery/hardware or something terribly wrong with your linux. I use linux on all my laptops. In fact my main dev box is a Dell M1730. Now out of date but it’s such a comprehensive setup that I can’t readily migrate to an updated machine (and it’s powerful enough for my needs to why change?).
I have always found Linux to beat Windows hands-down on performance, lightness of overheads and certainly it’s not a battery drain! On the rare occasion that I need Windows, I run it under vmware very successfully.
Try a fresh Ubuntu (I prefer Kubuntu as I prefer KDE) installation. Ubuntu is brilliant at “just working”.
A big Apple advantage of course is that it “just works” and it’s also unix (BSD), so you get the best of both worlds, but at a premium price tag.