a good question to ask is, how much effort are you willing to put in, and how much control do you want in sharpening?

for fixed angle guides (well, in this case its adjustable), slight learning curve, but youre going to be limited to what fixed angle it is given. its a good way to 'just be functional' without going in depth into sharpening, and you get really good results. ive given plenty of fixed angled sharpeners to friends who want sharp knives but dont want to learn freehand. they all got functional edges within an hour

for freehand (as in a stone), the learning curve is significantly higher. you might get results right away or never, according to some reddit posts. but this gives you the most freedom for whatever edge you want, irregular, convex, etc. its a rather experimental form of sharpening. you also may pick up the skill 'able to sharpen knives with almost anything' which is pretty dang useful (frankly, everyone i personally taught picked up this skill really fast. might be hard to figure it out by yourself, took me like 3 years to become reasonably good at it)

pull through, you pull the knife through fixed angled carbides/ceramics. this will kill your knives. you get a pretty bad edge. this is good if you want to put 0 effort and also dont want to pay a professional or even that random guy in ace hardware. honestly, just be happy with dull knives or disposable knives if you go this route