I upgraded, because it will definately work for our family...we'll earn a lot more Disney dollars!
I have 2 credit cards and one (my american express) is hardly ever used unless I am booking airfare (We only really use it and keep the account to get free checked luggage!!! It saves us a BUNCH every time we fly and DH has tons of frequent flier miles from work, so we fly/travel quite cheap)
Our second card is our Disney Visa. I chose to upgrade it, because we put almost EVERYTHING on it. It works better for our budgeting to put almost everything on our card. We pay it off 100% EVERY month. We spend A LOT on this card. Groceries, gas, travel, restaurants, all of our utilities, clothing...you name it, it goes on our card. Two grocery stores that I frequent are actually listed as 'grocery' and I've never had a problem with my extra rewards...same goes for restaurants and gas stations that I use.
We love to do it this way, because our budgeting is SUPER EASY!!!! We simply look at the bill each month, look at the categories and keep track of what was spent.
We may spend $49 extra each year to keep the card, but we will more than get that back every year getting the extra Dis $$$. We take a Disney Trip every other year. This will be HUGE for our gift cards to use there/for our vacation!
Another thought that I had was this. Sure, we'll get the 5% back for 3 months, but I am also interested to see if we continue to get it MORE OFTEN than those with just the basic Disney Visa. You know those mailers that we receive that say "call/get on line and sign up to receive 5% (in certain categories) instead of the regular % that is normally offered..."
I, myself, believe that we will get the chance in the future to sign up for these extra rewards more often. I may not be correct, but I certainly believe that it's a possibility! And, if we don't- then we don't.
It may not work for some people. Certainly if they don't use the card often enough. But, doing the math- I know it will be a great bennifit for us. I am not a money waster of any sort! We'll earn ALMOST twice the rewards that we're getting now. I'm excited!
I just had to do the upgrade on the phone. What makes it worse is that I even tried to redo the upgrade online a couple of days ago just to make sure it went through and it told me that I had already done the upgrade. 
I have never had any problems with my card. Never missed a payment or anything so I'm very confused. I don't want to reapply because the $100 is definitely not as good of a deal as the 5% back in the certain categories for 3 months. I had planned to pay off our trip entirely, buy Disney GCs for our spending while there, and buy a bunch of Shoprite GCs to use for our groceries for the year to really maximize that 5% bonus period. The lady I spoke to this time said she will send me a letter that will explain it.
