If your front windows are tinted you will be in much better shape then I was.
When I had the top down the screen was pretty much gray, I couldn't see anything.
As far as security goes, when I had the soft top on I usually left the doors open and took the faceplate with me. Most car thieves know if they don’t see a face place its just better to move onto the next car. Also I would rather they just opened the door and go in rather than slicing through my security by saran wrap soft top.
After having the Kenwood I have decided that I’m going to get the Eclipse AVN5495. Same price but it has a built in HD and has NAV standard. With the Kenwood you looking at another $800-$1000 for NAV.
If you really wanted a pop out unit the Pioneer ACIC-N2 DVD has every thing the Kenwood has plus NAV and its about $600 cheaper.