I am considering getting a Pentax k100d because it accepts my collection of old lenses, my collection of old SD memory cards, and runs on AA batteries. I can get the European version for under $300, but I understand it displays Japanese rather than English. Does anyone have experience with this unit? Will a firmware upgrade (done via SD card) allow me to switch to English, or is there a fundamental difference between the two? For $300 it is a good use of old junk, but the American version of the same will cost about $500.