As I understand it, hot zones are basically there for people to catch up. I know there are some pretty lame ones for all the level ranges, but most of the issues revolve around travel time to the zone not being worth the xp improvement. The worst selection? My vote would go to just remove Silyssar, New Chelsith from Level 80 rotation. Travel isn't too much of an issue (though I do dislike Katta), but in order to get to your kill mobs you have to do the progression. Not exactly helpful for catching up. Just a mild vent...carry on...
