I've always used Kingston cards for my memory card needs. I've recently started buying Sandisk. Now no card manufacturer makes perfect cards. Some cards die. I've recently had the experience of having a Sandisk Card die on me. I've also had in the past a Kingston card die (an old one which I had had for many years).
Why did I move to Sandisk? Though it may seem strange, a brand cards generally work very well with the brands card readers. Sandisk has better, and a larger selection of card readers. I've had incompatibilities before (this isn't an SD vs. SDHC issue) and drifted towards Sandisks complete solutions.
So what happened to prompt this post? Kingstons cards are a better value, but not only that, they have a much better exchange policy. When I had my Kingston card die (or any one one of their computer memory products), Kingston ships me a replacement within 2 business days with a return package for the old card. This entire process is quick and more importantly free. Sandisk on the other hand does not. They told me it would take 2-3 weeks to get the product exchanged and it would be faster to take it to the store of purchase if possible. This is what I did. I was told 2 weeks. 2 Weeks plus having to go to the store vs. 2 days and the convenience of having it shipped to the location of my choice. Not only is Kingston cheaper, as reliable (in my limited experience) but they have a much better service policy.
I'll be moving back to Kingston from now on.