personally, I like them. mine were fine when they came, and have stayed fine in my porper since I opened them.
I do find it a little suspicious that you only have 5 posts though....
here's my quick notes on card warping and storage:
RE: Warping
Mine were fine out of the box. No warping or "click-bend" as I've heard it called. I have a couple of card clips (which they fit in fine minus the double backer) that I keep the opened decks that I anticipate using, so they're always flat when I take them out.
I'm going to be building a card cellar when I move, and I'll be posting up a longer dissertation on card storage. For the time being though, I'll give a couple of tips based on experience, and stuff I learned in the print industry about paper (simplified of course)
Ideally, cards should be stored in an area with low humidity BUT, since you'll be using them in places that will likely be more humid, you should let the cards balance out in an environment close to usage conditions.
The finish prevents (or severly limits the ability) to absorb moisture, so all moisture enters through the edges. This uneven moisture gain is absorbed by the grains in the paper, causing warping, However, if the paper is given time to settle (and more uniformily absorb the moisture), the cards won't appear warped.
Obviously there's a limit - where cards CAN be oversaturated with moisture in a High Humidity environment. The fibres will push up against eachother and irregularities will become more prevalent.
Keeping them in a Porper clip while letting them adjust to the moisture will give you flat cards that won't be warped. In essence, you're almost "training" them as they absorb moisture and forcing them to distribute the moisture more evenly.
Cards will also warp when you use them, because they absorb moisture from your hands. Make sure your hands are clean and dry when handling them. Things like lotion will mess them up bad, not only because of moisture, but because the cards will become oily.
In my experience, the stock most good cards are printed on (Bikes, Tally's, Customs) have a pretty decent elasticity and memory. Keeping them in a porper clip will prevent any long term damage to their form.
I've heard people to say to put them in the fridge, but that's a terrible idea in the long term because condensation will ruin your cards over time. The deck will be warm in the middle, cold on the edges and vapor will become liquid at the edges.
Keeping them in an overly dry place WILL straighten your cards, but they're going to warp again if the change is too dramatic in humidity. They need to be conditioned to the environment.
Bottom line: If your cards are warped let them sit in a porper clip in open air (as long as it's not overly humid where you live). With a bit of time they'll fix themselves. It's really convenient if you have 3 or 4 clips and can rotate decks.