I took cash our first trip (94) and even though we didn't have any problems, I took travelers cheques on all of the rest.
Why? in one word, Security. To me, the amount of money that I spend on our vacation to WDW is a large investment and usually requires months of saving. So if something where to happen (like lost/stolen wallet, or who knows what) I could have the money replaced and we would still be able to take our vacation.
Again we have yet to have any problems, but spending a few dollars to purchase the cheques is a great peace of mind. I have never had a problem with the cheques being accepted anywhere, except at a McDonalds on our trip down. In this case, I just went to the Wal-Mart next door and bought a soda and used the change to purchase our lunch.
One tip is not to purchase all large cheques. Sometimes the gas stations didn't want to take them or I had to wait for my change. Of course with the price of gas it'll take a large cheque to cover the bill.
As far as the Cheque card, I checked into that and there is a fee to purchase (same as the paper cheque) but what you have to be careful of here is the fees that some merchants charge to use a "debit" card and also if you decide to make a withdraw at an ATM, then you have to pay the bank fees, plus a fee for the cheque company. Of course, as the years have gone by, I have had to carry fewer cheques because now I pay for my hotel and purchase my tickets online with my debit card and usually purchase souvies with the debit card also. After researching, I will stick to the travelers cheques for security and carry a small amount of cash as well as my debit card.