I've found that temp control can be a total letdown if your atomizer doesn't have rock-solid connections between the 510 connector and the posts. That is, if the atomizer's internal resistance drifts by a mere 0.02 or 0.03 ohms, it's enough to throw the measurements off and get dry hits.
After many months playing with different TC mods and many atomizers, I believe that's the real secret: the atty. All of them are fine for Kanthal, but a good many of them are too shoddy electrically for TC. Not to mention, they often don't deal well with the increased current required by nickel wire. I'm pretty sure a lot of people - including Busardo - have had a bad experience with TC just because they've tried it with atomizers that are good enough for kanthal, but not for TC.
And then of course, even if the atty's internal resistance is stable, it's not necessarily good for single coil builds - which is the type of build that TC really is designed for. Dual-coil is doable of course, but it's really too finicky for TC if I'm honest. That reduces the number of atomizers that are suitable for TC even more, sadly. I'm sure a lot of people have gotten a good TC build going on their atty, but ended up disappointed by the lack of heat and/or flavor, simply because the atty sucks at single coil.
However, once you've found well-built atomizers that shows a constant internal resistance, and you have a stable connection from the board all the way to the nickel wire, TC becomes surprisingly reliable, easy to build and forgiving. Then you understand how fantastic TC is.
Me, I've been extremely lucky: when my s.o. bought me my first TC setup, she chose an atomizer that was almost perfect for the job. As a result, I got to enjoy TC is its full glory from the first hit. I mean, honestly, I did my first build, fired, and fell on my knees because it was that good. Then I tried other atomizers and the problems started. But I wasn't disappointed because I knew what TC can do for me.
I can understand that, if someone starts off with the wrong experience, they'll dismiss TC as an unreliable gimmick pretty quickly - and unfortunately, it's more likely than getting a good first experience. But really, don't give up on TC too easily. Personally, I would never go back to non-TC mods. I just can't live without TC