Will a Micro SDHC card (& adapter) work in a Canon 500D? Any performance/quality issues? I tried with a card that I have, but it is a MicroSDXC (64Gb) and is not compatible with the 500D.
There is no reason I can think of that it wouldn't work. The cards are identical except for form factor. Pins/circuits/protocols are the same though. That said, unless you have a stock pile of SDHC cards lying around, it is generally cheaper to get fast full size cards than it is to get fast Micro cards. If the reason is to be able to transfer them to a Micro based device, then you may want to consider an Eye-fi card that could do it wirelessly.