While there is little difference in latency, the dual channel memory of the J&W MINIX means it has considerably better read and copy performance than the single 2GB stick in the Jetway motherboard.
Because eSATA and SATA come from the SB700 soutbridge, the performance is the same, but both are a fraction less than the standard maximum of 82MB/s that the GeForce 8200-based Jetway board achieves.
Unsurprisingly the USB performance of the AMD SB700 southbridge is hardly fantastic compared to the competition. If you have USB peripherals that are particularly sensitive to USB performance like external hard drives, then you might want to consider another chipset option like Nvidia or Intel.