Deb -- there are lots of different meds out there and they react with kids in different ways. You might find one that won't help at all, but the good news is that these meds get lots of research money and have come a long way with fewer or no side effects. After being at a school for learning different kids for 9 years I've heard lots of stories.

Since he doesn't seem to have the hyper part, he most likely will be able to take a smaller dose than other kids. There are even patches that can be worn instead of pills, though we've never gone that route. As Theresa said, finding the right dose makes a huge difference. We use the drugs that are XR, or extended release, so it slowly releases throughout the day, meaning one dose. (Though for Andrew, who does have the "h" part, he needs a small additional dose after lunch to be able to focus in the afternoon. Since Colby is so young his work isn't going to require quiet as much focus yet. As he gets older his dose will need to be adjusted to his tougher workload and change in weight.) It's also good timing as the teachers have had him for a while, so they know him well enough to help with feedback on what is working and what is not. We've always depended on the teachers for that advice, as it's hard to tell if it's working as we don't have them sitting still for most of the day concentrating on homework!
The "takeaway" from the doc visit sounds like with a little help from meds and some mods in school, he will do great as these kids may have a focus problem, but they are bright. I wasn't a big fan of meds at first, but when I saw what a difference it made in their confidence level and how quickly they started learning when on them, it became a no-brainer to us. Call or pm if you want more info.