I got my R4DS, stuck my microSD card in, and immediately noticed there's no "click action" like spring-loaded slots are supposed to have -- it just slid in and stopped, a la friction-based slots that have no spring. The card works just fine.
I'm going to guess that R4 had too many problems with spring-loaded slots and opted to switch over to friction-based slots in a later hardware revision as a solution. I say that I don't mind.
I'm going to guess that R4 had too many problems with spring-loaded slots and opted to switch over to friction-based slots in a later hardware revision as a solution. I say that I don't mind.