The PS4 unit uses the same internal relay for both Valve 4 and Heater 2 - you can't use both at the same time. I am not familiar with the P4 main circuit board, but at least on the PS4 main circuit board, if you don't need a Valve 4/heater 2, there is a fairly inexpensive way to use this 28 Volt AC output to control a fifth relay.
Also, the local display and remote displays are different between the P4 and PS4
Either the P4 or the PS4 is able to deal with Pool Only, Spa Only, or Pool/Spa combinations. However, P4 can only handle Pool/Spa combinations where the Pool/Spa equipment (filter pump, etc) is shared. The PS4 is a little more advanced where it can handle Pool/Spa combinations where there is separate (dual) equipment for both the pool and spa.
Also, it appears that the PS4 can do "Group" functions, which seems to be AquaLogic's term for a macro function. The P4 doesn't appear to have a "Group" function.
Remember that a base P4 (or PS4) still needs valve actuators (GoldLine GVA-24 or equivalent Jandy or Pentair). Also, the base units do not come with remote displays and/or floating (and waterproof!!) wireless spa remotes.
The best prices I have found (except for my lucky Leslie's Pool purchase) is $629 for a PS4, $79 for GVA-24 valve actuators, $165 for wireless spaside remote, and $269 for wireless table top remote at www.aquapoolstore.com. The best price is $115 for the wireless base unit is at www.h20poolproducts.com, alothough the first store is not far behind for this piece at $119. CAVEAT: I have never done business with either store, and I didn't have the time to compare shipping charges in this price search/comparison.
Thanks Titanium, thats a pretty thorough explanation.
I only have to control a pool filter pump, a solar panel 3-way valve, some lights and the chlorinator. No spa, and no "water features".
The P4 would probably be good enough for me then. I'm in Canada and to avoid being ripped off with duty "brokerage" fees (UPS, FedEx, etc), I generally try to buy my stuff from Canadian dealers. Unfortunately there's not a lot of Canadian online pool stores, but I did find one that lists the P4 @605$ cdn and the PS-4 @825$ cdn (shipping included). That's a bit more than what you are quoting, but still way less than the local pool equipment store.
Thanks for taking the time to answer my post.
BTW, I've also read through the whole P4 installation and operations manuals. My GF thinks I'm a freak
The P4 does sound like a good match for your installation, especially if the fancier local panel and the "group" (macro) function do not interest you.
Except for the chlorinator, you could get by with an old-fashioned Intermatic mechanical timer and a GoldLine Gl-35 solar controller for your installation.
My reasons for upgrading from my existing 23 year-old Intermatic mechanical timer and 8 year old GoldLine solar controller were as follows:
1. The metal case of the Intermatic mechanical timer was all rusted and needed to be replaced.
2. I wanted the remote control features that automation would bring. I got tired of getting out of the nice warm spa in the middle of winter in order to adjust the return and suction valves, and to fiddle with the spa temperature setting.
P.S. Regarding the GF thinking you are a freak: tell her you feel the same way when she goes out shopping for shoes.