Lisa,
I don't know why APU is doing well but I have a theory on why NRGY is doing poorly. NRGY paid a very high premium for their GP and then purchased a large gas storage asset at a relatively high multiple. I think they were counting on continuing growth in propane revenues along strong results from the gas storage facility to cover the distribution for the extra units issued for these purchases. Unfortunately the timing was not good for NRGY. I still think NRGY is a strong company, but it's in for a rough couple of years.
Jim