For starters, I'm on dexmethylphenidate (Focalin) and I haven't tried any other meds, so I'm not familiar with the effects of other meds.

In terms of positives, I've been on them for around 3 years at this point, and while they don't feel as effective as the first week I was on them, I'm still able to function orders of magnitude better when I've taken my meds. That said, it's not so much that I notice how much better I am when on the meds, it's more so that I notice how much worse I function when I haven't taken any meds.

In terms of negatives/side effects, one major problem I've run into is that consuming sugar and/or caffeine while the effects of the meds are still there causes me to become very anxious/restless, and it's made me keenly aware of just how much sugar/caffeine can be in the food I eat, so I've had to try and change my eating habits for when I'm on meds.

Another problem I've had is back before Covid moved everything online, I had to commute to school every day, and my meds would usually start wearing off around the same time as my commute home. The stress from the day + the stress from commuting + the effects wearing off left me in a depressed/tired state by the time I get home which was fairly exhausting, though it usually didn't last for too long. Obviously this hasn't been much of a problem since my university switched to online classes, but the effects of the meds wearing off can still put me in a somewhat tired state.

Blood circulation can be another potential problem (for my meds at least). My hands and feet seem to have naturally bad blood circulation, and sometimes it seems like the meds make that problem (temporarily) worse mainly in terms of making my hands and feet feel colder than usual, though that seems to be the extent of the problems for me. Circulation problems while on meds can cause much more serious symptoms than what I experience and can potentially be deadly, so if you have blood circulation issues and/or heart issues, then I'd definitely tell that to a doctor when discussing meds.

Edit: When consuming sugar/caffeine on meds, timing is fairly important. My meds last around 4 hours, and if I have sugar/caffeine in the last hour when the effects are wearing off, it usually isn't an issue. Having sugar or caffeine at the same time I take my meds really fuckin sucks though and can leave me in that anxious/restless state for an hour or two.

Edit 2: Also since you're on the fence about them, consider this. If you feel like you can function without them, then it doesn't really matter. However, personally I probably would've dropped out of university at this point if I didn't get medicated because it's incredibly hard for me to function unmedicated, so if you think you need meds in order to function then you should absolutely get them. It might take a while to figure out the exact dosage or type of med that works, and there's probably going to be some annoying or uncomfortable side effect no matter what you use, but the trade off is absolutely worth it.