I think the reason my husband has decided on the N1 and not the N2 is because you can watch a DVD on the front screen while driving on the N1. Since we don't have kids if we take a road trip I would want to watch a DVD in the front seat and not have to crawl in the back seat to watch something. My husband is happy that I want an in dash navi system because he wants to take my Bose 6 disk out and put it in his Titan.
I know what you mean about the new construction. My house was built less than a year ago and the Garmin Navigation System I'm have right now doesn't have my street or surrounding streets on it.
On buying something used on Ebay, that scares me as well. We will probably buy it from a retail store here. We have looked around and it is way more expensive but...at least this way if something goes wrong I can take it in there.