That was one of the biggest complaints I heard from my girls at CUSC about previous experiences--getting broken up, placed on different teams with different coaches, not having that continuity from one year to the next.
I was fortunate enough to move up with them from U17 to U18; of course some graduated and new faces cycled in, but I had a full three years with some of them. This past season (senior year for the whole team, as it happens) was also a reunion of players who had been together years before--it turned out to be their best, most enjoyable season and ended in the Cup finals. I think there's a lot to be said for continuity.