I have both a Kingston and a Transcend card in my collection. So I was running some tests on each today while also testing a new beta version of the U1MB BIOS and discovered something interesting with the Kingston card. First of all, partitioning and subsequent formatting is not reliable. Secondly ATRs hang when launched from the Loader, although they do show up fine either individually or in folders, they just don't want to run. Surprisingly XEXs work just fine whether in the root directory, or when nested within folders. So maybe I'll make this a gaming card.
The Transcend card so far looks good no matter how I use it, although it can be stubborn to refresh after hot plugging it. A good test would be to stream some video from it and see if it chokes on that.
All of my tests are being run on a 1088XLD.