You can get non-stop flights on UA between IAD and MCO. Or you can fly on US to DCA.
Neither UA nor CO offer quite the same opportunities for earning tons of reward miles but neither program has devalued their miles quite as badly as DL has. At least not yet.
You don't fly enough to get SWUs so international upgrades are gong to be a cash+miles proposition on CO (and I think the same on UA). You don't have to buy Y/B/M fares and hope the upgrade clears but the co-pay can be pretty steep. Plus, if you're redeeming for upgrades you're going to run into trouble trying to save up enough points for 4 TATL trips.
I generally like the CO program better than the UA program though if you are going to hit 50K miles the UA program is likely better.