I have a spare 4GB SD Card that I'd like to test for ReadyBoost so I'm not going to use it for anything else (format portability here is not an issue). As I've read, exFat is a very nice format because it's fast with deletes and free space allocations which I guess could help a bit with RB since it's cache and I suppose it does a lot of deleting/free space allocating.
I can see that default format is FAT32. But would it be better to either format it as NTFS or exFAT?
What would you suggest and what's your experience?