I really like the concept of strongholds. It forces me to think about creeps in combat, which I didn't do until now, because towers where enough to defend invader in owned rooms and I just evacuated remotes with short notice.
I am completely with @artch: The strongholds are no more of a problem than another player appearing nearby. They allow newbies like me to train for attack without the risk of being steamrolled in revenge.
Although I liked @Totalschaden's idea of different shards when I saw it initially on slack. I now see it a little bit different. The official server with its three shards provides the reference platform, and thus should include all features in an up to date version, as it does. Running with different rule sets is what the private servers are for. So @Totalschaden if you insist on a world with a different rule set than the latest, feels free to open a server.