I will now change my comments on the thread about HP ripping us off. It would appear that my original point was absolutely valid. Those who disagreed did so almost entirely on the basis that the ps models don't qualify for the rebate.
Well, they do.
Everyone who bought the Z3100 without APS, or who bought the APS separately, could have saved $800 by waiting only 60 days.
The entire premise of that thread has been vindicated.
Over at HP, the z3100 44" base model is $6,295.
The z3100ps GP 44" model is $7,495. So the printers are still $1200 apart in price.
Looks like the 24" ps model is priced $1000 above the non-ps model.
Some websites are showing the ps model for sale at lower prices, but all the ones I found say "backordered" or some such asking you to call for the price.