I got my Samsung Focus yesterday and I put a 16GB Kingston Class 4 micro sd card I bought from Amazon and have not noticed any performance issues such as lag, slow loadtimes for apps, or any device re-boots. So far everything seems to be working normal. There is only one annoying issue: I have been navigating the marketplace from the phone and doing a lot downloads, and on two occassions the marketplace froze on me and booted me out to the start screen. I tried getting back into the marketplace but it wouldn't load, the only solution was to restart the phone each time.
UPDATE:
*After the Marketplace did this twice and I restarted the phone, I have not had any more issues and have been navigating and downloading apps without any issues. I'm just curious to know if anyone has encountered this?*
UPDATE:
*After the Marketplace did this twice and I restarted the phone, I have not had any more issues and have been navigating and downloading apps without any issues. I'm just curious to know if anyone has encountered this?*