I've got the 9835 and I must say it is ******* awesome!
I was going to buy the 9815 last year, but I got in an accident and couldn't afford it. So when I went to get it at the beginning of this year I played around with the 9835 and was sold in minutes! heh.. The bio-lite screen is sweet, I would never again buy a deck that doesn't have a graphical lcd, it makes configuration and usability easier than ever. Plus its just plain cool.. lol