You would probably notice that your skills would improve quicker by purchasing an iwata, it makes a huge difference learning with a tool that you don't have fight with, an eclipse woukdnt cost you too much more than your ultra, even if it cost twice as much, the leg up it gave you would be well worth extra cost, as I understand it you travel a lot so you might well end up in a place where you could find an eclipse at a rock bottom price.
I'm sure that if you got the chance to try out an eclipse or any other iwata, within a few minutes you woukd likely be wondering how you managed all this time without it.