Our pool is too close to the house for a fence, less than 10 feet I think, so for the wife a fence was never an option.
So, before we had kids, we had a safety cover installed. Because of the layout of your pool and the walls around our pool equipment, we had to go with a "semi automatic" one.
Would have much preferred the automatic kind, where the cover is on rails, and one push of a button to cover or uncover the pool, but depends on your layout. And they do cost more money, neither option is cheap but can't put a price on safety and babies.
So now the "kids" are 19 and 21, the dog hates water, so we no longer have a safety cover. Depending on who makes them, how much sun they get (and they are probably/hopefully better now), I think we got 3-5 years from a cover before it started falling apart and leaking, so we did go through a few of them while the kids were growing up.
My covers all had little tabs holding them down, they have to drill into your deck and mount little plastic things into the holes that the tabs go into. Maybe 4 feet apart or so, all around your pool. You have to pull them all out, they give you a tool to unlatch them, then I had to fold up the sides of my cover, and then I could run the motor to uncover the pool. After some practice, takes maybe 5-10 seconds to undo each one.
To cover, you need two people to pull the cover out from the reel, and then one person (me) can put all the tabs back in place.
So one person can uncover (but easier with two), but it takes two to cover the pool. Probably 5-10 mins to cover/uncover the pool.
This type of cover will cause you to use the pool less (at least it did for us), but it was the price we paid for peace of mind. Having the uncover the pool to use it means you use it less.
This and cost are the major drawbacks, to me.
Advantages
It really is safe, you could really walk on it (but not recommended). As long as you do all (even most) of the latches, then pool is absolutely safe.
Acts as a solar cover to keep pool warm
Drastically cuts down on chlorine lost to sun, and water lost to evaporation. Saved me a bunch over the years in bleach and water costs, but nowhere near enough to pay for.
Algae can't really grow because no sun gets to your pool. Well it can if you REALLY neglect the pool for many months (like all winter long), but with a few days of shocking per TFP, pool is clear and nice in no time.
I have a fiberglass pool, so between this and the cover, I literally did nothing to the pool for months, and was never an issue. Just needed a week are so in the spring to bring it back.
Other stuff
Water on the cover. Yes, when it rains, you will get water on the cover. They give you a pump, and you put the pump on the cover, and it pumps the water off. The pumps have an auto off switch, so when the water is almost all gone, the pump will shut off. I did have to brush some of the water towards the pump, to help get it off.
I never considered this a safety issue, its really not more than a few inches of rain, and its hard to imagine even a little toddler drowning in this little water. You can also run the pump in the rain, to keep too much water from accumulating on the cover.
BTW, now that I no longer need an expensive safety cover, I bought a cheap winter cover, and connected it to my cover reel, and am using that instead. It doesn't let light through, so has a lot of the same advantages for chlorine and water savings, its easier to roll up as its just held down by water bags and jugs full of water.
Hope this helps.
Randy