monet -- if you are on Concerta, I'd assume you'd already have experience studying, since most schools are pretty well into the semester. Unless you just started taking it.
No experience with any stimulants, but I just started Strattera and it seems to be helping so far. The downside is that it hasn't been on the market for very long, so there's no information on long-term effects. Also, it takes a few weeks before it's effective, as opposed to the instant difference people feel from the amphetamine-based drugs. BUT, it is nonaddictive, doesn't give you the afternoon or evening crash that some experience with the short-term stimulants, and your doctor can call in refills instead of you having to make an appointment and sitting in a waiting room for an hour.
One thing I have heard is that for people who have been on stimulants such as Ritalin for a long time, Strattera doesn't seem to work as well as it does for newly-diagnosed people who haven't used other drugs. But then, methadone doesn't really "do it" for a lot of heroin addicts, either ... 😉