I've never used the K-97 before but do have some as backup for my Wyeast 1007. I ferment my Alts at 61-62 range. Since I bottle I dont know about the keg stuff, but I find they're great to drink two weeks after bottling.
My favorite recipe is Maris, Munich, Pils, pale chocolate, Carafa II, and CaraAmber. However, the Dusseldorf recipe on Briess Malting is very very good and probably the more traditional recipe. For variation I'll make that recipe next time.
No matter which, its a great beer style and every variation I've made got great comments from friends that tried it. I think it'll be a regular in your queue rotation @Jdub!
I only have one instance of experience to refer to, but I really feel like it's a moneymaker to allow it some extra Lager/conditioning time. It was difficult then and probably would be more difficult now to put that into practice though!
used K97 German Ale yeast. fermenting at 65 degrees in my ferm fridge. we'll see how the finished product turns out. i was going to follow the normal ale schedule: 2 weeks ferm and one week in the keg. perhaps i should consider letting it sit in the keg for awhile longer to condition. all i have to go by are @Cato's pix of his altbier. looks good!