Mike,
VS pumps have changed how people operate their pools and it is a lot more than just ROI.
With a single speed pump, you basically want to run your pump for the shortest amount of time possible, due to the high cost of operation.
With a VS pump the opposite is true.. I have a 3 HP IntelliFlo pump that runs 24/7, mostly at 1200 rpm. The cost to do that is less than $20 bucks a
month.. And my pump is about 12 years old, newer pumps are much more energy efficient. In my case I has a SWCG and love making a little chlorine all the time and I love skimming all the time. I like the look of my pool when it it not 'dead'...
Timers are not required with VS pump as they have control panels, or apps, that tell them when to run and how fast to run.
The downside to VS pump is the initial cost..
With a single speed pump you had to try to match the pump to the pool and filter.. With VS pump, the bigger the better as the bigger the pump the more water you can move at a lower speed. The lower the speed the less noise they make.. At 1200 rpm, my pump is so quiet, that you almost have to touch it to make sure it is still running...
It is easy for me to spend your money, but here is a good one...
Thanks,
Jim R.