Almost there except for a few quirks

The system setup:

IVA-D310R (European version)
DHA-S680P DVD-changer
TME-M770S 6.5" Touchscreen Monitor (Rear)
KCA-420i iPod interface
PXA-H701 Multimedia Manager
Rear View Camera
Alpine Amps, Speakers, Sub - 5.1 setup

Overall, a nicely integrated system except for a few complaints, which, however, can be rather annoying in day-to-day use.

I. DVD CONTROL

1) TOUCHSCREEN DVD MENU OPERATION
IVA-310 does allow you to just point at menu options tapping your finger right on the screen to select them, instead of using the remote/onscreen keypad to move the cursor around - very impressive on the verge of magical (menu position "coordinates" obviously vary GREATLY from disc to disc - beats me how they did it!)
HOWEVER:
* Hard to pinpoint if menu font is small
* DVDs with menu options located towards the bottom of the screen (about 1cm/half-inch) are hard to operate because that area is reserved for bringing up the hidden buttons.
* Only works for controlling DVDs in the Head unit from the Head Unit's screen - have to use the remote for navigating DVDs in the DVD-changer; note that the rear monitor (TME) doesn't have this feature either.
* More fingerprints :)

2) PAL/NTSC DVDs peculiarities

The IVA will correctly identify the system of, and play the DVDs inserted in IVA itself. Switching PAL/NTSC on DVDs in the DVD changer is a rather laborious two-step process:
The DVD-changer is not autosensing - have to long-press a remote control button for teh DVD-changer to switch.
Then you have to tell IVA the signal being input from the changer to one of its AUX is of a specific type (PAL or NTSC) - except it requires you to press about 5 or 6 on-screen buttons to get to that option hidden four levels down in its labyrinth of a menu system.
US users are unaffected since they get all their movies in NTSC, and most of you people (regrettably) couldn't care less about European film industry anyway :) But us Europeans do have to suffer. My point is, Alpine figured it out how to do it automatically on the head unit - why not use the sma ealgorithm for AUX connections and integrate your own DVD-changers better?
BTW, the TME (Rear) monitor is autosensing also.

II. i-Pod integration.
The (little that is) good:
* Large display good for seeing more artists/albums/playlists to select from.
* A nice touch - sorts items alphabetically ignoring the article "The" - very thoughtful.
The bad:
* PAINFULLY slow scrolling! I mean, pathetic!
* Will not remember the last position selected - you always start from letter A. (A trick - scroll UP to get to Z right from A - saves time)
* WHATEVER HAPPENED to search by the song?! My previous in-dash 1-DIN Alpine unit had it - the 4x more expensive large-screen IVA doesn't. The solution suggested by the unit is to organise into playlists.
We DO do that, but once a playlist is selected - you only get ONE chance to see the list of songs in it and select the one to start with. But once you hit the song name and it starts playing, there's no way to again invoke the list of songs in the playlist - if you hit the Quicksearch button, instead you get the ARTIST/PLAYLIST/ALBUM initial screen again - ie start from scratch! All you can do is BLINDLY use the forward/backward button to jump between songs. This is VERY annoying if you are into iPod integration.

III. OTHER
* No dedicated "Mute" button - this IMHO is a major omission! Imagine driving along, getting a phone call, and having to depress the volume knob for 2 (!) seconds to mute the sound. Doing a short-press invokes a bass/treble/fader/balance screen. Yeah, sure, we all love to just constantly keep playing with those setting, while playing it loud, and with the Alpine sound is so marvelous who'd want to mute it?
* I'm only half-joking there, because the fader/balance control is actually very nifty - you get your boring up/down left/right buttons and a graph showing you the end-result, but wait till you figure out you can actually drag the cursor (=fader/balance setting) around the graph using your finger and hear the result along the way! Stupid and pretty useless, but good for showing off and fun :)
* The Alpine TV unit will not receive the Russian SECAM broadcasts (Sorry, folks, you'll just have to live with that! :)
* Forget the hype about the "UNIQUE" Pulsetouch feauture - the screen clicks and "vibrates" when touched - you will tire of it in a day or two and turn it off.

OTHER than the above, the IVA and the other components listed somehow made driving the ultimate driver's car: the flaming black '05 Ford Explorer... less of a drag :)

IV. VIDEO/AUDIO Quality (responding to Bob pvreditor's comments)

The unit has a built-in light sensor and a broad-range dimmer sensitivity control. One can therefore adjust how bright the display is during the day, and also the "dimmest" level it will automatically switch to at night. The default settings work just fine.

The video quality is mediocre due to relatively low resolution of the display - they say it;s the price you pay for touch-screen functionality. If video quality is of importance, go with the 900 non-touch-screen model. IVA-310's videos suffer from jagged lines and illegible text at small font sizes in DVD menus as discussed above. However, I don't think it's all that important:
This is a head unit, and the driver not supposed to be watching videos while driving anyway (if the unit is properly installed, the playback is only possible while the handbrake is engaged). Ease of use offered by the device with a LARGE TOUCHscreen is much more important. The solution would be to install a larger ceiling-mount screens for the rear passengers. In this regard, the head unit serves its function of the central hub very well. For example, the driver is listening to his iPod/CD through the speakers, while the rear passengers are watching movies on the rear screen(s) with headphones, both able to control their respective sources simultaneously, and independently.
So, yes, the video quality of the screen is mediocre, but it doesn't really bother you.

The audio quality of the _system_ is of course, only as good as its weakest link. I went for higher-end Alpine components (speakers, sub, amps), and is very satisfied both with 5.1 and stereo sound. The head unit does NOT have built-in speakers, nor does one really need it. The TME rear monitor does - the sound is awful, I can only imagine one using use it for the voice guide with the optional Alpine navigation system. Music playback is awful - so I turned it off right away.