Sony’s first UHS-I card is a disappointment, while Delkin’s second-tier card is a great reason to stick with their top-of-the-line product.
Sony’s new UHS-I 94* MB/s card contains a disclaimer (yes, the asterisk is printed right there on the label but only explained on the packaging) that the rated speed is read only, and that write speed is “lower” (but not how much lower, for good reason). While I haven’t attempted to measure the read speed yet, the D7000 RAW Burst Test results are disappointing (2.1 fps, 18 MB/sec), and I can’t recommend this card for high-speed shooters.
Delkin has re-branded their card line to follow a “Good, Better, Best” rating system. While their newly-badged “700X” card presumably has the same characteristics, or better, as their former Elite “633″ card, this “600X” pairs a high claimed read speed of 90 MB/s with a claimed write speed of 30 MB/s. It may indeed reach these rates in some sort of test equipment, but certainly not in the D7000 RAW Burst Test. Results of 2.3 fps and 19 MB/sec are not very impressive.