The only real difference is that paper tickets ordered through somewhere like undercover tourist are refundable...whereas the e-tickets are not. Of course, you get the e-ticket immediately, whereas it will take up to a week for the paper ticket to be delivered.
I also used undercover tourist for my tickets and they are great. One benefit to them that I have not seen mentioned is that purchased from UT code as travel so they can be purchased erased with credit card points that off set travel expenses such as the Venture card. I did this back in Oct and erased all 3 of our tickets with the points we had saved up.
Undercover Tourist has one with Universal Studios, but not Disney. $30 statement credit for charges over $150. I just ordered our US/IoA tix for our May trip using this deal yesterday.
Maybe the UT deal has had the terms changed. I used it earlier in the year to buy a Disney ticket for a family member and I did receive the statement credit for that Disney ticket.
Undercover Tourist has one with Universal Studios, but not Disney. $30 statement credit for charges over $150. I just ordered our US/IoA tix for our May trip using this deal yesterday.