Maybe there is something wrong with me but Universal, even with EU, does not look like a full week visit. The two current parks can be done in 1 day with express pass and 2 without. EU is going to add another half day park ride wise that will likely take a full day for the first year while everything is still new. So, while I could see it taking a day, we are still only taking 2-3 days for all three Universal parks and that is if someone doesn't choose to drop US or IOA instead of a Disney park.
I admit this could just be me but serious questions to the people who think this is going to make a big difference. Why is EU different than previous Universal parks that did nothing to slow the ever-increasing attendance at Disney? How is it going to capture the demos that Disney dominates like older visitors, parents with young ones and childless couples?
If Disney closed two thirds of their hotels, bulldozed the Magic Kingdom, razed Blizzard Beach, set most of Disney Spring on fire, took a wrecking ball to the entirety of DVC, and degraded their in park food another couple of steps then they would be roughly equivalent to what Universal will have on offer once EU is done.
I'm just not convinced it will have the long term impact people are expecting but I'd love to be wrong about that because it is great for all of us if Universal and Disney have to fight for our vacation dollars.