I've done 3 or 4 days with the Track Daz crew. They are a bunch of good guys, but they don't seem to be very selective of who registers for their days.
My experience with them is that the people (riders) don't know how to follow instructions (i.e. ignore flags), and ride way beyond their means.
They used to call a riders' meeting because some crashed, the red flag is out, and people ignore it, so a riders' chew-out meeting is always called. Since then, they've started holding afternoon riders' meetings just to refresh everyone's minds.
Don't get me wrong, Track Daz is a good bunch. They are still learning how to put on a smooth track day. I totally believe in giving them your support so they can learn and continue to provide quality track days.
As far as Button Willow, it's a neat little track. It took me about half the day to figure out the track (my first time), but it's a nice fast AND technical track. Elevation changes are... like fore mentioned, simulated.
But take my word for it, it'll be a blast... and start getting expensive.