I have been using an SDXC 1 class 10 (Sandisk Ultra) on a LE1700 running Windows7 and it has worked fine as an exFAT file system for the last months. In the LE1700 the speed is limited to around 5.5 MB/s in read mode and around 3 plus some MB/s in write mode but I find it very useful. Those figures are for copying files between an SSD drive and the SD card. The CrystalDiskMark-3.0.1 results for this card are: Seq.: Read 3.3, Write 6.8 MB/s 4k: Read 2.4, Write 1.5 MB/s I don't know if this important, but I am running the Ricoh SD/MMC host controller, version 2009-06-25 22.214.171.124.