I agree 100% with Executor. I have the misfortune to currently be stuck in 3 (well now 2) endgames. Its sad how similar they are - clamming, blood stones, etc with all the micro that entails. I spend more time rounding up gems than I do planning battles...uggh...its just not fun.
I will only join games without gem generators going forward. I don't mind Tarts as much, since they do help nations without decent national summons and open up some fun magic path combos that allow for creative scripting. They certainly don't make anyone invincible - i just lost 2 to the AIs 800HP Kraken in one game.
But they do give a pretty big edge to whoever gets the Chalice.
That said, the more I play, the more I realize that just finding certain sites early on can pretty much determine who wins amongst competitive players. I am starting to wonder whether no independent mages or OP sites like Steel Ovens should also be a part of a balanced game, though that would take away a lot of the fun of site searching.