I use mine in a Nikon D300 and also have several Delkin UDMA CF cards. Even with a super fast SDHC card in the adapter in see just a tiny shorter time until the memory frame buffer fills up because the memory card can't empty it. The only time that has any practical effect is if I shoot more that 15 frames at the fastest continous shutter mode. Other than that it works beautifully. I purchased the adapter so I could use SDHC cards while traveling. The SD cards let me offload directly onto a 64GB iPad and I don't have to carry a laptop. The read times on the iPad are faster than the CF card read times on a laptop or desktop machine.