No matter how easy to cope with changes are, if they happen all the time, they are annoying. You are supposed to mess around with programs for a while to really get to know a language, but if at mid-point you are forced to stop and rewrite everything, it's like being stuck on 2nd gear.

However, I now understand three things: (1) Arc releases don't really come that often, (2) changes won't be neither numerous nor drastic and (3, really important) former versions of Arc will have taught you a bunch of valuable lessons. 3 is pretty obvious, but I was totally failing to see it. Thanks for that.

Guess I will learn Arc :)