It depends on what you consider "worth it". The solar cover will make the pool warmer and reduce chlorine lose to the sun burning it off. They also help to keep dust and leaves out of your pool they won't keep everything out but it does help to stop some of the stuff.
If you find the solar cover difficult to handle or a pain to remove and put back on then you likely won't use it very often. If you aren't using it because its not easy to use then you likely won't consider it "worth it".
I always try to recommend you plan ahead for an easy way to get the cover on and off the pool. This generally means some sort of cover reel.
It cuts down on evap too We only have a 15' pool, but we do think it's worth it. We swim in the evenings and weekends, so not having to spend extra time "cleaning" (as noted by @CJadamec ) is "worth it" to us.
If your pool has issues staying at a swimmable temp, it could be worth it, but if it doesn't, it might make it warmer. Our pool is under lots, and lots of trees.
This is my first pool/first year with it, and I have a solar cover in the barn. I will be swimming almost every day/night with wife & kids, and to help with evaporation I will use it for that purpose. Might be a pain putting it on/taking it off every day but the pros outweigh the cons for me at least!
Our cover goes on after swimming even if using the pool daily, we got caught by a cold front one year lost 2 days of swimming because we didn't put the cover on one night...…...
I made a "solar reel" out of 4" white pvc drain piping, 3 pieces of pipe and two couplings, it rolls along the top rail fairly easily. I added a handle to one end this year to make it easier to use.
To get the cover to stick to the pipe I simply wet the "roller" down with pool water, friction does the rest.
We use it to prevent temperature loss overnight, especially at the start and end of season when running our heat pump. For that, yeah, well worth it. It saves like 3 degrees of temperature loss overnight, which translates directly to money saved on heating costs.
If you aren't heating, it will still work to keep your water warmer by eliminating the overnight temp loss, if that's something you want.
I decided after the 2nd time taking my solar cover off that it wasn't worth it. Anything that collected on the cover dumped in the water when I removed it and I had no real place to store it once off. What a PITA is was! I'll just eat the heating costs, which are admittedly substantial probably cost me an extra $100/month to heat without it. I have no place to store a cover really either without it being really obvious. We also like to sit out by the pool and drink margaritas at night. I don't want to look at that cover. For us really it was purely a financial decision. For my $85k the bottom line is I am not too terribly concerned with an extra $500/season in heat loss enjoying my oasis.