While it's possible you have discovered some exciting new problem, Eclipse is likely more your problem than the JVM. I've never increased the heap size of IntelliJ from its default size of 750M except when dealing with extraordinarily large Scala projects. I've had Sublime Text use more RAM than that with some plugins.
I prefer VIM, but I still need Eclipse to do my job effectively due to circumstance.
Like Eclipse only plugins whose functionality I would have to take time I can't justify to duplicate. Plus the additional maintenance cost of the dev team no longer having a homogeneous environment. All to allow me to be able to... do what I already do.
Don't get me wrong, I'd really enjoy taking a week to explore the options and put together a better development environment for myself and my team. I do make improvements where I can already. But we're already an effective team despite Eclipse's flaws, the RoI just isn't there from a business perspective.