A couple of days ago somebody posted this comment regarding RubyMine on Reddit:
I can't find a way to show Terminal (not ruby/rails terminal) in RM, but in Aptana I get it as a window inside the IDE, for rails development this is a huge bonus as I need have only one app open.
RM on mac annoys me by having dialogue boxes that are not sized, so to read the content and use them the first thing I have to do is resize the box. This is a minor annoyance, granted, but I'm trying to work, not play with the GUI.
Back to the terminal, running rake tasks, generate etc, is much easier from the command line and without having to cmd+tab from app to app I see what's going on when I hit return.
RM only lets me see one project at a time, it needs multiple instances of the GUI to have >1 project open at once, Aptana lets me see the entire file structure in the navigation frame. This is useful if I have an abandoned project that I need code from in the new version I'm making.
Aptana lets you import Textmate Rubles and themes. +1 for Aptana.
Aptana is free, even though I have RM free for a year on an academic license, I much prefer Aptana.
Another small annoyance with RM, when a major new release comes you have to install it beside the old one, then delete the old one, it doesn't update itself.
Aptana 3 is just getting better and better. It's my IDE of choice for everything that doesn't need C#, and it's built on Eclipse so you know there is support and integrity behind the builds.
Some of the problems mentioned in this comment might be outdated and only apply to RubyMine, but this one I think applies to all IDEs that are somehow derived from IDEA: "RM on mac annoys me by having dialogue boxes that are not sized, so to read the content and use them the first thing I have to do is resize the box."
I have had this problem for years and I've always thought/wished it's gonna be fixed in the next release. But it's been more than 5 or 6 years and dialog boxes are still so small that not all their content is visible when they open up. This is especially annoying on high resolution screens with a lot of real estate.
I hope you guys fix this in the next version or so!