While the PX was DESIGNED for powered speakers, (you can tell by the preset list
)it will most certainly do amp/speaker combo's. After all, the driverack has NO way of knowing if the speakers are powered or passive... It still has standard crossovers and slopes, just no alignment delay.
If however, you don't intend to bi-amp those tops then there isn't any reason for alignment delay for the tops. However, you DO have 10 feet or so of delay to use for top sub alignment with the PA+
The older DRPA was the same color as the PX but it isan't white as you suggest but almost chrome... brushed silver.
The DRAP+ has by far the best auto EQ algorithm.... and is much more "foolproof" where setup and auto eq are concerned.
As I said before, protection is the 260's game.