It seems to me that a track day will teach you how to handle your bike very well, but won't teach you real world riding awareness. A track, I'd imagine, has things like groomed surfaces, no traffic, no cagers, no stop signs, traffic lights or any intersections at all, etc.
I've never ridden a track day and I'm not saying that they aren't extremely helpful, but I would imagine that the MSF course should arguably be the first stop for learning to ride on the road better.
Am I wrong on my assumptions for what a track day is?
Yes. Racetracks are not billiard-ball smooth, groomed surfaces. Sometimes, right after repaving or new construction, they can be pretty nice. Chuckwalla is said to be pretty smooth, for example. But most tracks have rough pavement, seams, pavement transitions, and all kinds of challenges. Traffic? Try being swarmed by a group of riders who've been waiting to get around you are are being good boys by waiting until the straight, or a place to pass on the outside. Or being one of the guys who's waiting for a spot to squeeze through...
On-road skills are learned, hopefully, at a driver's education course. Bike handling skills are learned on a closed course where those distractions aren't present.
MSF courses are all about theory, just like track days, really. We can theorize and discuss until the cows come home and go out again but practice is what makes us better riders.
For example, on the -09 forum, three riders have gone down in the last week or two. In every case, they've suggested they were at least partially at fault.
It's our ability to physically handle the motorcycle under emergency conditions (sudden stop or quick maneuver) that will ultimately make the difference when the sh*t hits the fan. That's what we can learn from riding in the dirt and training at the track.
MSF teaches strategy, shall we say, while track days teach tactics.