What I have now is an old Jandy APURE1400 with a dead front board and cell with about 5 months of use on it. It seems you can't get parts easily or cheap for these anymore so I want to just replace the whole thing. I've had to do a fair amount of work on it, from changing from a two port to the three port plumbing, some dead sensors, the occasional fast scale buildup and finally the dead control board. The scale likely was my fault as my pH control has not been the best, I have one spa to pool waterfall that runs when in pool mode circulation and two sheers that I keep off most of the time, plus I had (remodeled at the end of last pool season) limestone masonry that was constantly flaking into the pool. I added acid a lot but really didn't keep up 100% of the time (terrible about the non-swimming months). That said when it was working it was great, water quality was top notch and chlorine levels were very stable.
I was looking at the Hayward AquaRite Pro as they have pH control built in, but I'd like to know how well they work and if it's just going to be another maintenance job waiting to happen. It looks like the CO2 or acid will be something to you have to buy and refill regularly, I'm not convinced that this is better than pouring some Muratic acid in the pool every weekend.
Compupool looks to be inexpensive, has a good warrenty and you can see the cell to check on it.
Pentair seems more expensive but you get new control electronics along with the new cell so you don't have to worry about which is bad or if you can still get parts. The power center seems unlikely to change.
Finally I could ditch the SWG, keep salt in the pool for the feel and use a tablet feeder or something like that. I assume I'd need to add acid less often then but I might be opening myself up to new problems.
It's be a plus if I could fit the new system in the existing unions as well, not sure if any of the brands use the same size. I assume I will lose Jandy PDA control with any of the above options but at this point I'm fine with that as I'm fairly sour on Jandy at this point.