We did this in November and it was really great experiencing so much in one trip (all first-time things for our family). But I must say out of all the new things we did this trip, Osbourne Lights were my favorite!
If we won, we would probably choose DL because we have never been there and really want to experience Cars Land. For us, going to DL costs as much as WDW, so it is not worth it in our eyes, but we'd take an (almost) free trip (we would still have to pay for a few kids tickets, extra accommodations and food). We have APs to WDW and would not fly, so that trip would almost be not worth it unless we could save the free tickets to renew four of our APs at a later date.