SmartQ has SD (and only SD no internal memory) all the other with wolfson do not have SD at all, odd that, its like the wolfson has nicked the space usually reserved for the SD card and the fact that the smartQ has no internal memory at all means you lose out on a possible 8GB as it only accepts sd cards and their top is 8GB = catch22 here
apart form the Q i can think of no others at all with SD and wolfson .... do ipods have SD card slots, they use wolfson also???