I think they're very good if you use your computer for a whole lot of typing and nothing else. Using a DVORAK keyboard instead of a QWERTY one will also improve your WPM and QoL when typing, once you're used to it. If you're a writer or a programmer, it's worth considering.

But much like DVORAK vs QWERTY, any non-typing tasks become affected. It's awkward playing PC games, for example, when some of your shortcuts for inventory/map are far enough from your kb hand to need your mouse hand. You also don't have much range to choose from, so may have to make compromises on things like keypress feedback, simultaneous presses, unit price, etc.

I learned to touch-type on a tented keyboard with a mild split. When I replaced it, I got a 'Wave' keyboard - not split, but slightly tented, and had depressions and curves to match the wrist and the finger lengths at rest on the home row. Both of them were membrane keyboards (full-depth keypress). Despite being a membrane keyboard, the Wave was still as chunky and loud as most mechanical keyboards.

But now, I'm just using a generic full-length mechanical keyboard (partial keypress) with relatively quiet switches, one chosen as a good compromise between gaming (sensitivity) and typing (feedback). I've changed my resting position a little so that my wrists are still in an A shape (not an H shape), but I'm finding the keys much more comfortable.

The old ergonomic keyboards didn't give much choice and in hindsight the feedback on the keys on the Wave felt AWFUL compared to what I use now. A split/tent mechanical keyboard might be different, but then price becomes a consideration. Swapping to a mechanical keyboard made the biggest difference to my comfort typing. (And don't let tall/loud keys fool you - not every chunky keyboard is mechanical.)