Tino: GREAT question. I used to wonder the same thing. I dont like to sit in coach unless, as noted above, the flight is < 2.5 hours.

I've used a combination of 500 mile certs (new 1k, so haven't really experienced the confirmable ones yet) and miles. But I've found that the extra 40,000 miles or so that I flew last year (taking me from premex to 1k) made for a great multiplier of upgrade certs and miles.

Since upgrading is the most imortant thing to me, I am more willing than most to use miles to upgrade (particularly int'l...when they let me based on my fare but also on transcons on smaller planes). I also do try to schedule travel around widebodies and 757s to ensure availability 48 (and now 100) hours in advance.

So now when I sit in the back it's cause I'm on a short flight, I'm not paying H or I'm on a last-minute trip...