I have decades now (shit, I'm old) experience with these tyoes of devices in professional settings. There are two classes now, one with direct drawing over screen, the other indirect one. I have my brain and muscles trained for both, and I'd rather take the former than latter any day. It's more natural and in some cases necessary (hand-drawn animation is way slower by indirect method, if impossible).
Having said that, I'd only consider and compare three devices (there are more). Cintiq attached to a computer - fantastic experience and highly non portable and requires a lot of space. Allows for photoshop, which is still no 1, as well as pro 2D animation tools. Portable wacom/cintiq which is a pc in a fat tablet form.. not that great (heats up, battery, fat), but allows all wibdows tools you need.. and then there's ipad pro with its pencil. Procreate is fantastic and saves the show on the app front, apple pencil and screen surface is subpar experience to wacom nibs and surface (not cintiq one!!), but it takes like half an hour to get used to it and never give it a second thought. There are screen overlays which mimic wacom surface though, I just don't need it. Also, ipad pro has the advantage there of having less space between the tip of the pencil and the surface being shown (less of a gap between glass and drawing) and that amazing refresh rate is, well, amazing! I have "unlimited" budget for these things and my first tool to grab for drawing and painting is ipad pro. For animation and matte work (where you need different tools), it's cintiq on a windows machine (why not a mac is a different topic altogether).
Which leaves the Cintiq, and when I used one, I thought the screen quality couldn't touch the iPad, plus it's at least as expensive for a single-purpose tool. It wouldn't surprise me if the Cintiq's have caught up with iPad on that dimension now, my experience is about seven years out of date.
They truly are. One thing I might also mention is that in my experience, the wireless connectivity is less than great for Wacom tablets. Way too much lag. I recommend using a wired tablet if at all possible. It may be that this is old advice, but I couldn't deal with any lag whatsoever when using one for hours at a time and disabled the wireless mode of my Intuos 4 (yes, it's quite old, but still works fine)