Yes, you can use the 4 way for page flipping too.
I have to agree with Russell, the slider bar was way too stiff at the beginning.
But now it's very soft, sometimes too soft. Accidentally touching the slider bar could flip a page. Putting it in my Jetbook pouch definitely flips a page or two, the slider is too responsive, and I prefer not to use it unless absolutely necessary, as I see problems with it in the long run.
Also the bottom left 2 buttons are becoming slightly blacker. I think it's corrosion appearing from finger grease. The buttons themselves are still shiny, but instead of a silverish color, they very faintly start to have a darker shine.
I used 16GB SD cards just fine, 32 GB would work as well, but I'd advise you to stick with 2 or 4GB.
Those cards are more than large enough, and if you load a too large library on the jetbook, browsing through menu's goes too slow (as well as loading menu's goes a bit slower).
I bought my jetbook about 3 months ago, and it came with the latest FW.
This site sells similar devices really cheap. The Astak EZ reader pocket pro is very similar to the jetbook, and perhaps also worth investigating (perhaps worth investing in, since you can buy them at a much cheaper price than the other readers)!