We use cloth diapers, but I know some people who had terrible diaper rashes with Dry Max (people who have always used Pampers and who change their kids as often as they did before and only got rashes when Dry Max came out).
Most babies seem to be okay with Dry Max (if your baby is, I wouldn't worry), but some have really severe reactions, with boils and blisters and everything. I know the US Consumer Product Safety Commission was investigating them, but I don't know if they've come to any conclusions yet.
One theory I've heard is that the Dry Max diapers are a lot thinner (this is part of what Pampers advertises about them) ... taking out some of the extra padding leaves the chemicals closer to the skin, where they can irritate the skin more easily. I don't know if it's true, but on the rare occasion we use a disposable, we've steered clear of Dry Max.