I agree.. for airlines with electronic upgrades.. if you go over 140,000 or 150,000 or whatever, you get a credit of Upgrades. (ie 15 one ways for getting to 150 K).... Or... ($150.00 off Airport club for 150,000 in one year..) but one thing to consider... seriously, is the alliances.
The alliances make life easier, but I believe some of these perks would be based off of UNITED only or AMERICAN only miles... but it is kinda neat..