I don't know what servers you are playing on, but in the region I play on I get the least amount of lag I get to any server I have even connected to-and I have possibly one of the worst internet connections around. As for crashing, I'm not sure what servers you have seen crashing-but as far as I know, none of the servers have crashed for weeks.
With every new release, the devs find new ways of reducing lag, making the plugin more and more efficient-this is what makes more servers possible (more server resources free)