I've played on a few, eternium, magicwow, and a couple others, but the biggest fallback for me is I love running 5-mans, and on most servers, either:

1. It's blizz-like, and there aren't enough people on to have a decent pool for instancing 5-mans,

or

2. It's high-drop rate (which is cool) but people feel that it's a waste of time instancing since you lvl up so fast.

Are there any private servers out there that are great for 5-man instances? I'll bet there are others who are looking for this as well, or have found it. Appreciated.
*by high-drop rate, I meant high drop/high xp rate, hence fast lvling* -thanks again