My wife is a cold sleeper and I'm a hot sleeper. So generally, if I'm comfortable, she's cold, and if she's comfortable I'm hot. At a compromise temperature neither of us sleep as well as we would at our preferred temperature.
For the past few years, we've been using a water-based mattress topper implemented dual zone Climate Comfort Sleep System, and it's worked out great. We can both be very comfortable at the same time and sleep better as a result even though there is a significant difference in our temperature preferences. I'd say in general this type of system is more comfortable and better controlled across a wider range of temperatures, but that the initial and maintenance costs are much higher, and there is substantially more maintenance effort with this type of system over an air based system. These systems are so effective you can save money on heating and air conditioning as typical room temperature has little or no impact on bed temperature. When we "upgraded" to the latest version of this system recently it magnified the differences mentioned above but the cloud-based subscription and software controls made it so unreliable we returned it.
So we tried a BedJet 3 air based "Dual Zone Climate Comfort Sleep System for Couples" along with a "cloud sheet. I was a bit skeptical as to if I would like it given several things I had heard in reviews. I was worried it would be too noisy (and it is noisier than the water-based systems), but you don't tend to use it on "maximum" overnight and at lower settings its fairly quiet. I was worried about the blankets hovering over your body like sleeping under an air mattress, but as long as you have a comforter or blanket on top of the "cloud sheet" its nothing like that - it puffs up, particularly at maximum, but at normal speeds (we tend to use between 25% and 50% fan speed) the covers still sit on you as they normally would. My final big worry was that I wouldn't like a constant breeze under the covers, but with the cloud sheet at medium settings, the effect is so subtle you don't feel any breeze, and just enjoy the perfect temperature.
So with the bed jet we have a simpler, less expensive system that still gives us a great sleep that’s perfectly reliable and takes little to no maintenance. And setup was much faster and easier than water based systems. On the down side, there is a little bit of overhead on laundry day taking the air nozzles in and out of the cloud sheet, and ensuring the nozels and cloud sheet are adjusted to good effect, but it isn't much different than stripping or making a normal bed (maybe a couple minutes longer). Also this system is more sensitive to room temperature, particularly if you are using it to cool, so you likely wouldn't save any on air conditioning (as the cooling capacity is pretty anemic), but you could save on heating costs. I'm a pretty hot sleeper and as long as room temperature is about 70, it has enough cooling power for me - at temperatures much higher than that I find it doesn't quite do the job though.
Overall, it’s a great product that provides a quick and easy, and relatively inexpensive, reliable, and effective solution for particularly hot an/or cold sleepers and I would recommend it.