The most annoying thing is what you've called "Block Lag" where by as you destroy blocks they keep reappearing then disappearing again and it's just in general very frustrating.
Today I spent more than an hour trying to track down what was causing these issues on our servers and I believe I've found the cause and fixed it. It was a whole bunch of plugins that when combined together cause a lot of processing load each time a block is destroyed or placed.
I've removed all the offending plugins and the servers are now running a lot smoother. We've not really lost any functionality either as most of the problem plugins were related to stuff that runs in the background that you don't see in the game itself.
If you experience any performance issues with the servers don't hesitate to reply here or tell me about it next time you see me on the game servers or in the IRC.
Thanks
