I've never used miles for upgrades or FC tickets.... only for coach tickets.
Some people here swear that int'l upgrades are the best use for miles... but I'd rather fly in coach with a buddy than in FC alone.
I've never been to or through Denver.
I've always had 3 hour or longer connections in MSP, and I go through MSP often as a NW/CO Elite. I'll always override the automatic 45 min. connections so I can spend a few hours at home having lunch with family. (I grew up 2 miles from MSP, on the bus route from the airport to downtown Mpls.)
[This message has been edited by Viajero Joven (edited 06-29-2001).]