Turning on "raw buffer cached" made a big difference, bringing the recycle time down to less than five seconds.
I tried chdk RAW. UFRAW flunked, but Raw Photo Processor opened and worked with the .crw file just fine. Not noticeably faster, though.
Benchmark:
SD Card Class 10 Class 4
====================================
Raw 7262 3785
Memory 9998 5365
Write 64K 3276 3156
Read 64K 5479 5479
All Kb/s
I find it odd that the cards are almost identical when reading and writing a 64K block to the SD card.
As for counterfeit, who knows. This is Thailand. Rolexes, DVDs, Viagra, you name it, we fake it.