Started out with Adderall a few weeks ago at the start of the semester, then after noticing no effects, switched to concerta (aka ritalin).
Personally, I initiated the prescription because I'm starting my first year at college, and I want to have every safety net available. I only take the meds on days I have classes (2 days of the week), because I have class all day on those days.
So far, it seems to work at the beginning. The jolt of electricity I feel is enough to make my brain stay focused on something for a longer period of time. The after effects make it difficult to sleep, and my appetite is greatly reduced (not a bad thing).
Eh... not sure really what I think about it right now tbh.
Hope I answered your questions.