If you think you will ever shoot rifle, that's where it will shine. For pistol, since the precision of handguns is typically around a fifth that of rifles, the advantages in cartridge alignment over a more conventional press will be harder to discern on paper (though I can think of a couple of examples that go against that). There are a couple of areas in which it will still be advantageous over the presses you've already had, though. One is the die quick change. It literally takes no more time to change a die than putting a case in the shell holder. If you are used to having to unscrew and screw in a die ever time you change it, this will seem like real breath of fresh air.
Another is the priming tool built into the Co-ax press. For high reliability priming it is hard to beat. The one-at-a-time aspect of it is slower than most most people loading for handguns will put up with, but that's because of the volume of ammunition they are shooting. It sets the bridge on primers optimally for sensitivity and reliable ignition, and that helps accuracy if you are shooting match grade guns.
The Co-ax's simple spent primer drop tube and jar captures primer dust better than any other presses I have.
To your question: did you over-buy? Well, maybe. Do you really need a press like this to load good handgun ammo, no. But will it make highest reliability and highest accuracy ammo, yes. Will it be quicker and more convenient than a screw-in-die single stage press, yes.
So I think it comes down to the quantity and type of shooting you do. If accuracy and reliability are a main purpose and you are not producing and shooting hundreds of rounds a week, it may be a reasonable choice. But if you are producing hundreds rounds a week, you will probably be happier with the time you save using a progressive press. I don't think you'll find the non-indexing turret presses especially faster than the Co-ax press. I own an old Lyman turret that I have to index manually, and I always wound up batch processing with it anyway because putting cases in and out of the shell holder seemed quicker and easier than rotating the turret. The newer Lee turret press with auto indexing would be better, but I figure that if volume is your purpose, go progressive and get a completed round with each handle stroke instead of four. YMMV.