Hey Mark

Thanks for the observations and questions.

To answer your questions-

-The pump is significantly quieter than the previous pump. It does not sound (smell or feel) like it's working hard at all.
-1.5" pvc plumbing all around
-2 skimmers are combinded into one line near the pool (I dont like this- but its under the concrete deckin, so tough to modify)
and main drain has its own line. - so its two intake lines controlled by a pentair three-way valve at the pad.
-There appears to be a small bit of air in the pump (If you are familiar with the Pentair basket-pot window, the air pocket is about the size of one of the 'pie slices'.) Do you think I am gettting air in through an underground or above ground union on the suction side?

Additonal info: My completely blocking either the skimmer or the main intake via the pentair valve had no appearant impact motor noise, air in the basket, or PSI.

I may try to pressure test the suction end. What would a DIY need to perform this test? If not possible, what would a ball-park cost in NE US be for a pro to come out and perform the test?

Again - thanks for the tips!