The shape is a bit different, but both boards work as intended. Both have LEDs, but the Gravitech LED is on whenever a card is inserted (I think using the socket’s mechanical card detect switch) and the Adafruit LED blinks while data is transferred to/from the card, which I think is the more useful function. Both have “push/push” type sockets (to release card, push in, it clicks and springs back out). They are from different vendors; the Gravitech sockets seemed to have a bit more friction and were more sticky overall, and tend to grab on to the cards rather than release them cleanly, but they seem to improve a bit after a few cycles.
Looks like we did good, our LEDs blink on data transfer and our sockets release cleanly out of the box The SD sockets are always hit or miss depending on the maker.
jbeale in the Dangerous Prototype forums is doing a series of comparisons, the previous one is “comparing Sparkfun and Pololu 5V boost circuits“…Related