That's always so subjective. Personally I like the biggest discount I can get, that leaves more money in the budget for other parts of the trip if it's not spent on this part, right? In general that's what I go for.
However, when it's this close, there are times when going for the short term "loss" gains you more later if you have a particular redemption that needs UR points. If that extra couple hundred (or thousand) points from charging a Disney resort purchase hits a threshold that now saves you hundreds on a flight (or something) it might make sense to do that rather than save tens from the DGC purchase. I think it's specific to each situation. For me, I'd run the numbers with the total volumes you're looking at.
So an extreme example, I think
@calypso726 threw out a $25,000 Disney number once while explaining why she goes more for UR than small discounts. If you did that at Target 5% off gift cards, you've banked $1,250 in savings to be applied elsewhere. But if you instead bought the same amount of DGC's at a store with a 5x UR rewards category, that's now 125,000 UR with the same base value ($1,250). But this turns into $1,875 in value if used through the portal with a CSR, and probably a lot more if transferred to a partner. Thus, depending on your goals, it can make sense to "forego" the higher discount in the right situation.
That's extreme but that's why I suggested you run numbers on your particular volume. It might be a wash and you go for Target as it is just easier to account for
(or you find out you only need 600 more UR to get a flight on Air Force One (or Space X, what's cooler now-a-days?
) and so the CSR wins this one, hehe)