Thanks, sbm.

Correct on the IAH-LIM-IAH & IAH-PHL-IAH and also correct on not needing the final PHL-IAH leg to qualify. I would get it on December 30th's IAH-PHL leg.

Since I live in Houston now I thought of booking as one and taking the 1605hrs flight from IAH to PHL. That gives me 9 hours of time to factor in the usual lateness of 591 from LIM and time to go home and change and sleep a little before going back for the Philly flight.

I just didn't know if there were advantages or disadvantages to booking as a whole or doing 'em separate.

Fares for IAH-LIM are shockingly low for Christmastime, by the way. Last time I checked those numbers they were in the $1500-1600 range.