The 9857 has what seems to be a lesser version of the Bass Engine Pro which is featured on the 9855 unit. With Bass Engine Pro you have a 7 band EQ, to name just a few. I don't think the 9857 has this exactly. With the Bass Engine Sound Tuning on the 9857 you can alter the bass and treble frequencies only. Which is the better buy?
Hard to say which is the better buy because I haven't seen prices on the 9857 yet. It wont be released until March.
However, I think the most important thing to consider about the 9855 is not the equalizer, but rather the glidestrip at the bottom. The glidestrip is what enables you to fine-tune the equalizer settings.
Many people have been frustrated by the glidestrip because it was either defective (early release models) or maddeningly infuriating to control. You should definitely try it out and see if it is something that you would want. Personally, I think that it makes the radio more difficult to control and this is an important factor given that you will likely be fiddling with your radio while going 65mph on the highway.
The 9855 seems to have way more features. I don't even thing that 9857 has a motorized face. I've got the 9853, and comparing it to the specs of the 9857, even it looks like it has more features, including the motorized faceplate. And the msrp for the 9857 on their site is $400 us and $529 cnd which seems a little steep considering my 9853 was $390 cnd retail. I don't know why people complain about the glide-touch being so difficult. It's like pushing a button, but instead of pushing a button, you touch your finger on a spot underneath an option on the display. What the hell is so difficult about that? It may be an unnecessary feature, but I don't think it's any reason not to buy the deck.
I made the choice and got a 9855 while I could. The 9857 has no EQ, no time correction, and no optical out to use with the PXE-H650 (which my stereo guy said was my other option, when it comes out, with the DVA-9861). Yeah, DVD-A might be nice with the 9861, but I'd rather have the 9855. And it's better than 9857 for sure.
actually the cda9857 is not their top of the line unit, so you are comparing apples to oranges. you would have to look ath te dva-9861. the cda9855 is not so great with their glide touch. you knwo they had to revise that thing 4 times in one year, tells you how bad that thing is!