Best DVD Navi for the money

I am currently looking into DVD Navi units and have noticed that their seems to be two pretty good ones on the market, Pioneet and Alpine.  Question is which is better?  Here is how I would have it installed.  The main unit would probably go in a shelf in the trunk.  Main display would be mounted low in the center consule.  To those of you familiar with the new Accords I was thinking in the CD compartment, since I don't use that.  How accurate are these new systems?  Anybody have one?  Ever had any issues?  I would use mine primarily for car trips with the wife, easier to find points of interest etc.  I would also like to be able to use the unit as a DVD player to save money for right now.  Do they both play DVD video?  Would they both integrate well if i wanted to add a other screens and maybe a dvd changer at some point?  I want to integrate all this into the factory stereo as I do not want to change the factory in dash changer.  Last how expensive would it be to have somebody make a box or plate to put in the cd holder so as not to truly make this a permanent install but still get that look.

check out this short thread, it keeps me from having to type all the info again.

https://www.the12volt.com/installbay/forum_posts.asp?tid=9765&PN=2

-Cy