X10's programmers wrote both AH and AHP.
I used AH/CM11A until my system was upgraded to WindowsXP, when the motherboard problem that popped up hit my machine and I upgraded to AHP/CM15A. I noticed no difference between my AH or AHP as far as how modules and timers. I had no macros under AH, but now have a single keypress macro that turns off all units/lights on three different housecodes.