Yet other people's brains implode whenever they try to play EC but after half an hour on a melodeon can stumble through half a dozen tunes.

The push/pull thing confuses me for a kickoff - I can't imagine learning a tune that way. Chording seems like it should be easier, but isn't. I tried to work out some basic chords on a B/C melodeon (to accompany Blackwaterside, after Tony Rose) and to me it was like something out of the Crystal Maze - "so you can get that note on the push but not *that* one... OK, so if I play that chord on the pull, can I do the next one on the push?..." (I wound up needing longer arms - eight solid bars of push chords. It would have been a lock-in.) On the other hand, I know melodeon players who say the B/C box does *their* head in.