Either one will work great and do what you need. It is just brand and automation preference.
Pentair Vs Hayward Salt Chlorinator – MY EXPERIENCE
I have had a Hayward system for more than 10 years and it has been nothing but pure joy. I recently replaced it with the T-15 cell after 7+ years of use, for less than 400 bucks. That brings my chlorine costs to less than $57 per year for a 20k pool.
Hayward offers total control of the output settings in 1% increments, and a display that basically provides users with some useful diagnostic information. Plus, there are lots of pool owners using this device on forums, the internet and many countries so expert advice is easily available. The only con I have seen so far is the routine cell replacement at 5-10 years but this can be bought online for a couple of bucks and easily replaced.
The Pentair on the other hand has a limited chlorine output control if you don’t use it with Pentair automation system. Plus, the replacement cells cost more due to the electronics in the cells. However, it is durable and high-quality too plus it is more forgiving on high salt levels.
The Pentair continues to produce chlorine in high salt conditions and does not need a partial drain to dilute salt.