I played in all of the rounds which had reduced in cluster eta - and I've been on both sides of the farming. So I speak from experience. If you can think of any reason that I'd lie about it please share it with me.
Having said that, the experience was better when we had massive clusters (by current standards) - the cluster wars back then were bigger (and more fun) than the whole game is now.
As for R21/22 - I remember arguing against the reintroduction of in-cluster attack ETA bonuses back then too.