Honestly, I haven't noticed a huge difference with either the temps or the burn time. If you take off the lid, I've noticed the temp spike seems higher with the lump. However, I can get my drum to cruise at whatever temp I want regardless of the fuel. One nice thing about lump is way less ash to clean up.
Gotta say, I've had outstanding experiences with the Frontier lump, contrary to some other posters around here. Fine stuff, especially if you can get it on the cheap.
-elbows deep in someone else's misery.