They ALL played like crap. Only server that was ever good was some french one (probably since it had FR and pl were screaming "merde" on it ). The ping was quite high compared to others (70-80), but it played incredibly well. Every hit was properly registered and only few awkward situations ever happened. The best netcode i've ever used was in UT99 considering its age. And still is if i take Killing Floor as an example. Bunch of players and hundreds of monsters everyone have to see in the same spot and it's still bang on unless the ping is slightly higher where you get a constant delay. But once you get used to it it plays fine.
well, the game provides you with the tools to see who is at fault.
net_graph will show the server framerate, the rates, your fps, choke, spikes and what's causing it, etc. it's close to the end all in what you need to figure out where something is going wrong.