[japper88]

I don't think it generally makes a difference. Although some programs just won't run properly if installed on the SD card. Google Maps should work fine off the microsd card.

I installed SD Tuneup (attached) -install to device
and it's supposed to speed up your phone's access to the storage card.
(not actually sure if it makes a difference, but hasn't caused any problems for me)

Also, remember if you take your microsd card out the programs installed on them won't work.