I'm looking to replace the Monsoon HU in my 2004 4mo with a nav unit. I'm looking hard at the Sony XNV-660BT or the Kenwood DNX-6960. Anybody have either of them? I'm interested in first-hand experience, not brand biases or the like. No disrespect.
I don't know if you'll get any specific feedback about those models, but I have a slightly older model of the Kenwood you referenced (DNX-7140). I'm very happy with it. There are some things in the interface that I would change (and maybe the current generation of Kenwoods have improved in this area), but they really are minor complaints. Overall, I like the Kenwood, mainly because the Nav interface is made by Garmin, which I've been using for years. It was instantly familiar to me, and very easy to use. I don't know how Sony's nav capability and interface are.
Also-- I picked up this older model as a refurb (works and looks perfect). It was a fraction of the price of the current model Kenwood. I think I paid somewhere around 350 for it (can't remember exactly), while the new model was somewhere around 4-5 times that amount. it might be worth looking around if you're willing to live with a model that's a generation or two behind. It still has all of the features of the current model (bluetooth with mic, Nav, DVD, iPod, Sirius/XM, external A/V input, TV tuner capability, USB input, etc.