I fly AA for short flights just about every week. I have earned Platinum statues with 210k miles so I am certainly not anywhere near their their top tier but a regular and loyal customer. I am trying to actually use some of those miles and for me it’s terribly confusing the changing points which always seem to be the highest on the dates I want. And with a plan to fly into Heathrow I have been seeing $500+ fees in addition to the miles (an AA person told me something about LHR having lots of fees or something).

I only need a one way ticket from LHR to ORD (around July 4th ironically) and would like to fly business class for this leg. I am trying to decide between cashing in a bunch of miles to lock this in OR the option where I book economy (still looks like there is room in economy plus thankfully) and, as I understand it, within 24 hours of the flight they will tell me if I am upgraded at which time I will pay something like 30k points plus $350 fee if I remember correctly.

I realized this is a really general question and my results may very, but has anyone attempted this type of upgrade (versus locking it in by paying the extra cost and miles upfront), and if so how likely and I to have success? I am trying figure out if I have a decent shot, or no chance at all and I need to secure business class upfront.

Any suggestions?