I bought the Pioneer DEH-P835R one year ago. I am VERY satisfied with this head unit, it is GREAT! The sound is superb if you use an external MOSFET amplifier. The internal amp isn´t so good, but I don´t blame them for that. Have you ever seen a head unit´s built-in amp that sounds good and loud like a class-A MOSFET amp???
It has plenty of controls that include BASS/MID/TREBLE/LOUD and even a Subwoofer active low-pass filter that you can select 50/80/125Hz, level from -6dB to +6dB and phase switch. The tuner has RDS, a very nice improvement over conventional tuners. It has the DFS alarm wich I say would not stop the thief, but will sure give him a bad headache if you set it to the internal speakers. Yes, you can also set external relays to fire a siren and blink the lights.

Besides, the look... Yes, it is awesome! The color graphics EQ display (understand here: it is only a display, doesn´t adjust frequencies) is a show, specially during the night. The buttons change from green to orange when you access the options menus.

And most important of all: I think the price is fair, considering the good sound quality, functions and ease of use. Great value!

One good advice: do not buy the "DEQ-P800" hide-away DSP. It degrades the sound quality, the instruments positioning becomes messy, bass response gets weak and worse of all, in some CDs it just can´t handle some more complex sounds, introducing noise and sometimes clipping outputs.
Removing the DSP brought me back the awesome purity of the DEH-P835R.

This is probably the best stereo I have ever owned. It is clear, loud, and has so many options the manual looks like an un-abridged dictionary. The only thing which has bothered me is the plate over the display. When the sunlight hits the face, it become almost impossible to read the display because it has a mirror efect to it.