I just received my US$19 32GB SD card from Hong Kong (yes I know) and did some speed tests. Under benchmarks, I'm getting 16.5 MB/s READ and 3.6 MB/s WRITE. In real-world tests (copying a file from my hard drive to the card), I was getting WRITE speeds of 3.2 MB/s. I picked up the card as a secondary (or primary card depending if I'm doing any all-day festivals) for my original Edirol R-09 (v1.31 firmware with accepts 32GB SD cards).
From what I do understand, this benchmark is more than suitable for 24/48 recording. I just want to make sure of this before I lose an important show.