I have a 9818. This year's model is the 9819 and it includes DVI. I don't know of any other differences, but it is possible they "fixed" a constraint with the component inputs (see below).
I LOVE the 9818 on NTSC. I read a number of reviews indicating that Philips does good with NTSC and 480p signals. And I thought PP was damn impressive. I ended up getting mine as a refurb at electronicsnation.com. It's the only way I could get into that model. As such, the XBR800 was also out of my range unless I could've gotten a similar deal from Sony for a refurb, but I didn't find such a deal. So it was easy to choose.
I've heard the Sony is better at HDTV, but with a 34" screen, HD is amazing, and I can't imagine it can be too much better than what I see, unless the Sony had much better color reproduction. I certainly think HD is jaw-dropping, so there is no way I could justify the $$ difference that I was looking at.
I'd seriously look at electronicsnation.com -- they had 2 in stock last week.
So a little more in-depth:
1) PixelPlus (PP): This is great. And simple (no setting it up like the DRC palette on the Sony). This does such a good job, I seldom watch DVDs on progressive anymore. There are a few DVDs that I think look better on progressive, but only marginally so, and when using PP, the Digital Natural Motion kicks in and really makes pans and slow movement less jumpy. I know some people like the progressive more, and some like PP more, it's a matter of taste.
2) Zoom modes. I think these are good, I leave it in Automatic most of the time, which seems to work good. When Enterprise comes on, it automatically fills the whole screen with the letterboxed picture (I couldn't find any other zoom mode that did this, only automatic). DVDs (anamorphic) of course go on Widescreen. One problem, inputs AV3 and AV4 don't allow any zoom modes. You'll get full widescreen off of those.
3) Inputs. My model has a pretty good array of inputs (AV1 is composite or component 480i, AV2 is composite or S-vid, AV3 is component 480p or 1080i, AV4 is component 480p or 1080i, side input is composite or S-vid). This works OK (DVI ould be nice), except that AV3 and AV4 are 480p or 1080i, and AV1 is 480i only. This means there is no input that is both 480i and 480p. For my DVD, I hook up composite to AV3 for progressive and s-vid to AV2 for interlaced with PP. This is kind of a pain to switch modes, and I only get to use s-vid with PP, AND I end up waisting an input, which will become a problem someday. This constraint, and the lack of zoom on the HD inputs are the two things I hope they fixed on the 19, but I don't know about that.
4) Some other minor things that I don't like: The OSD does not allow you to show the volume graph when in minimal mode. In max mode you get it, but then the channel number or input is ALWAYS on and I can't deal with that, so I can never see the volume graph. I was never able to get the sound set up so that it worked the way I wanted it. I wanted a mode on the TV that turns off the internal speakers and let me use my receiver. I wanted this as a mode so that I could use the TV speakers for casual viewing when I was too lazy to use the receiver (or when the wife and kids just watched the news or cartoons, etc. But to do this, the setting was not quite right and the volume on the TV or receiver had to be WAY up when using the receiver. I finally got it another way where this is better, but the TV speakers always stay on, so I have to mute (which puts a mute bug on the screen) or (what I do) turn the volume all of the way down when I'm using the receiver. This is a little bit of a pain.
5) One other thing, I have not found anyone who has or can easily get a service manual, so there is not an easy way to figure out how to make service menu adjustments if you need them. I kind of need to fix my TVs overscan, but can't find out how to do that.
Overall, would I buy the same TV again? Absolutely (unless I decided to get a front projector instead). The picture really is stunning. And at least on the refurb, the price was great. Oh, and by the way, my refurb had a strange problem that was intermittent that nobody could figure out, so Philips replaced the TV and now I have a new model (but one with too much overscan).
Good Luck, Greg