Haven't heard of the bmw driving day.. but I've been on the advanced driving course at Killarney.
I do it once every second year, so have gone through it thrice....
Don't think it covered as mch as the BMW day, but basically includes skid pan, driving test on the road and an optional track day.
It's always more fun when you're not driving your own car though, lol.
Especially on that skid pan... man that wall approaches you soooo quick!