As a "WDW Person" (I don't get to DL as much as I'd like, unfortunately), I can attest that the "refresh method," i.e., checking for cancellations, more often than not yields some really good FPP options. For example, the line at HM could be 45 minutes, but checking for a FPP might show one available, after refreshing the screen several times, in the next 10 minutes. We tested this at MK one day, where we started around 1PM, and by 4PM had done 14 major rides, just going from attraction to attraction, pulling the next FPP as soon as the current one was scanned. We also took advantage of the five-minutes-before window allowance. Only physical exhaustion made us stop, and by that time we'd proven our point.