Electric Heater without cover

Yes, this is true. But the cover/reel is also an enormous hassle as well.
We have family in south FL with a tiny pool that they heat and use in the winter, and dragging the cover on/off the pool is a reel (pun intended) PITA that kinda kills the fun of spontaneous swims.
If you have an auto-cover, it's a no brainer.
The reel and cover ABSOLUTELY is a PITA, but as much as I hate it, I would never not have one early, and late in the season. You lose way too much temp overnight. Just suck it it up, and do it. Unless you have money to burn.....literally.