Over the last week I have been checking envoy class seat availibility through flyaow and it seems to be very inconsistant and wanted opinions if that is typical. I am trying to best see my chances of upgrading day of with DS0085.

Flight info:
8:25P Depart Philadelphia-Int'l, PA (PHL)
8:30A Arrive London-Gatwick, England (LGW) May 20 US Airways 98

It has changed from 20-18-21-16-8-12-12(today)

thanks - t