I installed this unit in my vehicle the other day. While the Alpine with the 2" screen was attractive, the dealbreaker was the lack of a CD player. Here are my impressions of the the P7000BT:
Installation was fairly straightforward, although I had to scour the internet for information specific to my vehicle. If you have "diversity tuning" in your stock system, you'll be connecting the blue/white lead to antenna power on your wiring harness, and taping off the smaller secondary antenna plug. This head unit only has a single antenna input. Stringing the microphone is a little bit challenging - I used another wire to pull up the plug end into the console cavity. My OEM stereo occupied two separate single-DIN slots, so I had to purchase a universal single-DIN pocket for the empty slot. I drilled a hole in the back of this for feeding in the usb and AUX connectors.
The user interface definitely takes some getting used to, and you have to refer to the user manual on the included CDROM to be able to figure out how to control many functions. I like the simplicity of the design, but it definitely sacrifices ease of use. The one big drawback seems to be scrolling through a large list of artists/albums/songs. I'm trying to figure out whether there's a way to jump to letters quicker.
It works well with my iphone 3G. Some advise setting the stereo to where the iphone controls the music, but I've had no issues yet switching between calls and music. What I'm not sure about yet is whether AOL radio and Pandora will work this way. I'm guessing that I would have to switch to iPhone control of music for those to work.
The integrated bluetooth is one of the main reasons I bought this unit. Calls are clear and there's no noticeable echo, unless you call someone who's sitting inside the car. Then you can do some crazy echo effects. The way it works is as smooth as the iphone, and I'm particularly impressed that the head unit actually downloads your contact list from the iphone so you can dial straight from the stereo.
A wireless remote is included, which makes some functions easier, although it feels a little ghetto to use a remote control for something that's a few inches away from your hand.
the single-line display is a bit disappointing, but I can live with it. This HU doesn't feature the childish motion graphics you'll find on other stereos.
The music sounds quite a bit bitter on this than my stock unit. I don't have a subwoofer in the car (yet - I may get one) but it puts out a decent amount of power to the speakers in the vehicle. I'm looking into the blaupunkt underseat woofer as a possibility.
Overall, I think it's the best unit out there for iphones/ipods if you need a CD player built-in to your head unit. I'm sure better units will come out before too long -- that's why I waited until my OEM stereo crapped out before deciding what to replace it with.
