I go with lht645, thus I suggest you should pick EECH1. The
installation procedure is somewhat more difficult than you would normally have, but the community is really generous to help you. The quality of the new game is highly speculative, so it could be disappointing. It's a risk to take.
As your limited spare time counts, blast yourself through the installation is my advice. And then take an easy learning curve with the help of the community.
If you manage to know EECH1, it's probably not too hard to go into EECH2. I expect the same keybinds and gameplay. Only graphical and multiplayer enhancements are really the matter to make the switch.