The combo units genuinely solve the space problem if that's your main concern. You get the air fryer speed and crispiness for most everyday stuff, plus the full oven capacity when you need it. That said, the real question is whether you'll actually use both functions or just default to the air fryer side and ignore the rest.
Cleanup is actually easier than a traditional oven since the basket and tray come out, and there's less splatter since you're working with smaller batches most of the time. You're still dealing with a nonstick surface to be careful with, but nothing worse than what you'd get with any modern appliance. The seconding of what the other person said about constant use checks out - it does get used way more than people expect, especially once they realize how fast it handles chicken, fries, frozen stuff.
The catch is build quality varies a lot between brands, and some of these combo units feel like they're trying to do everything but excel at nothing. Read actual reviews on the specific model before buying. If you're replacing a toaster oven anyway and have the counter space it takes up, you're not losing anything. Just don't expect it to replace your regular oven for a whole meal prep day.