Just a brief note about the DesJgn cards. I used them for the first time this weekend, and the game in general liked them. They both complimented the back colors (I got the Green/Purple Mardi Gras set) and the feel of them. There were no issues with them being too slick as eneely said might be a problem as they were no more slippery than the DaVinci we had been using.
Given the price point and the fact I lost my hook-up for free DaVinci set-ups, I'll be going with these in the future.
I use Copag poker size cards in my home game. They are easier to shuffle, last longer, feel nicer. Nobody really cares too much, a few comments about the cards being nice. I like that I don't have to worry about the corners getting folded and creased or the cards getting wet. Pretty small investment for the convenience and longevity you get out of them.
IMO there is nothing wrong with using plastic coated paper cards like bikes, but they will wear faster, and you will probably have to swap decks at least 1-2 times during a game. I fairly recently picked up some plastic Copag's and they are very nice. I went with the Copags mainly because they are about half of the price as KEM's, and feel just fine to me.