Methylphenidate is the generic description for drugs in the Ritalin family. It's been used for decades - it was one of the "original" medications for ADHD. Well known lists of benefits and side-effects.
Some of the key advantages include the fact that it is fast-acting. Even the "long-acting" forms (Concerta, etc.) are fast-acting. They are out of your system in under 24 hours - usually, much less than that. Straight standard Ritalin (and it's generic forms) is out of the body in about 8 hours. Effectiveness of a dose is more like 3.5 to 4 hours. With this class of drugs, there is no ramp-up, no time to build up in the body. It works, at a given dose, or it doesn't.
in my opinion, it's one of the least-scary medications out there for ADHD. In our part of the world, it's always the first one given. And they tell us it is effective for something like 75-80% of the kids (and adults). Most frequent reason given for switching from the short-acting versions is "rebound effect", which kicks in when the dose wears off. Not everyone gets serious rebound effect. For those who do, long-acting versions like Concerta avoid multiple rebounds - leaving just one at the end of that dose.
I've been on this class of drugs for over 10 years.