AND THE WINNER IS.....!!
Tired of dithering around, I went and tested a few vehicles side-by-side, determined to finally make a decision. At a friend's urging I included the Land Cruiser (or, as my wife calls it, the "Land Bruiser") in my trials. Results....
Land Cruiser: Damn, is that thing big. It drives nicely, and I like the real 4wd it provides, but what's left of my environmental sensibilities wouldn't let me go for something like that. I could even handle the extra $$, but it just wasn't for me.
QX4: Didn't even take it out for a ride. That back seat is just unusable, as far as I can tell. My 8 yr. old son is not getting any smaller, and he already kicks the back of our seats when driving. I sat back there for a few minutes and walked out of the showroom.
RX300: The more I looked at it the less I liked it. Sure is comfy inside, and drives nicely but the lack of real 4wd in any mode, combined with an egg shape and not much room for those times you want to haul stuff from pt. A to pt. B made it too much of a compromise.
MDX: As compromises go, this was starting to look better and better. We went for a ride, and I really liked the handling and smooth power delivery (note: the salesman kept trying to convince me that it handled as well as the BMW X5. Nice try buddy, but I've borrowed my inlaw's X5 for a weekend, and nothing compares to that machine -- as long as you don't care about actually carrying stuff with you, as I do. So he didn't have to make that particular sale, and he was getting annoying trying to convince me of it...). The lockable differential at low speeds should satisfy my 4wd needs in Tahoe and, though it may be a little bigger than I need, I intend to keep this for many years and I figure my space needs will only get larger, not smaller.
So, and this will come as no surprise to this board, I decided to go with the MDX! The dealer said it would take 4-6 months for delivery, but when I told him that I didn't care about color (we'll see if the wife agrees...
) he said he could get me one in a few weeks. Hopefully it will get here in time for our next Tahoe trip!
Many, many thanks to all on this board who provided invaluable advice as I went through this process.