Completely agree with SpongeBob here in that the first thing you need to do is figure out
what you want to automate. If it really is as simple as "run the pump at this time for this long" then you should be good with just a VS pump as those usually have scheduling capabilities by themselves and pretty much all SWG's and heaters have flow switches. Simple is best when the needs are simple as well. Add a fancy pool light that comes with a remote and bam, you are golden.
In the interest of giving you as much information as possible to help you make you decision, here are the key benefits I've found by having an automation system.
- Easier Scheduling for better VS pump efficiency. The low RPM required to keep your pool clean under normal circumstances may be too low for the SWG and will definitely be too low for the heater. There are also times you will want to ramp up the RPM in your default schedule (pollen season!) or just need to temporarily alter a schedule. While this can all be done on the VS pump itself, it is much easier to create complex schedules from your phone.
- Heating Without A Schedule. I only run my gas heater when I know people will be swimming. Having a "push button, get heat" on the automation control panel (it turns on the heater and ensure the VS pump is at sufficient RPM) is huge for the WAF (wife acceptance factor). Again, this can also be done from the pad itself, but sometimes people just want an "easy" button.
- Remote Gas Heating. It's also been great to be able to turn on the heater an hour before we get home so the pool is ready for us.
- One Off things. VS pumps usually have a "hit button, temporarily bypass schedule" option. This is great for most things, but can be limiting if you are relying on flow switches to handle the on/off of SWG and heater. While not the make-or-break factor by any means, it is really nice to be able to tell your pool to "go do this for an hour" without worrying about how it will affect other components or schedules.
- Convenience. I have a set of jets in a seating area. We figured "oh, just get up and walk over to the pool pad" to turn those on or off or change the VS speed to make the jets stronger or weaker. This was a fine idea until you are actually sitting in the pool with a margharita in hand and say "man, I really wish this jet was on/off/stronger/weaker" at which point you start offering your kids $5 to go turn the nobs and press the buttons. After a few seasons of this, you've pretty much bought an automation system.
Anyway, everyone has different views on these things so take it all with a grain of salt. Good luck!