To each their own, but I never really understood the concept of this server. Why not create or join a level locked guild on live? Or mentor down and go to whatever expansion you want to. Maybe it is because people are forced to stay in that expac.? I am sure there is more than one reason.
On TLE you have everyone playing the same expansion so you can get groups for that expansion. There are people all around the areas, at the quest givers. The game feels populated. On live I can mentor and go anywhere, kill anything (more or less) all by myself. It has the feeling of a ghost town. We are on TSO now and the LFG channels are filled with people looking for current zones. I find it more enjoyable.
Mob tuning and xp rates are different on SH than live. If you look at live vs. TLE, where a mob is solo on live it'll be heroic on TLE, where it might be heroic on live, it's epic on TLE. On live you can go into a heroic zone at level with modern gear and everything will explode instantly on impact, on TLE the mobs (theoretically) will actually fight back. Daybreak just kinda sucks at getting this tuning right. Mobs are either way too easy (DoF) or stupidly overtuned (KoS). Joining a progression guild or level locking on live is a self imposed artificial construct. On TLE the server sets the boundaries in which everyone must operate.