I dont want to offend you, but an escalade, does it do what a 4x4 is designed to do? yes. It will not get stuck in the snow, it absorbs most potholes, so it is very cushy, specially on a long trip, and you can comfortably put 5 people in it, and another 3 smaller people in the back. However, on top of that, it is pretty fast, has a much bolder look than most other SUVs, and has a bunch of luxury features.

Is it a gas guzzler? yes, that is a byproduct of having speed and size.
Is it overpriced? problably, as it shares components with many other GM vehichles, but you pay for the Cadillac name. Is it useless? absolutely not, it is very comfortable to drive year round, specially if you have a familly, it is very quick for its size, and has a bunch of luxury features that you wouldnt find on other, cheaper SUVs of that size, and will show that you have money when you show up to a meeting in it.

As for your Skyline, as far as overpriced, $90,000 seems like a lot of money for a car that does 5.2 0-60, and has 275 horsepower. It seems like a lot because another car comes to mind that does 0-60 in 5.1, has 300 horsepower, and costs $25,000 (05-06 Mustang GT), Now you could argue that the Skyline has 4wd, but do you really need to spend an extra $65,000 for 4wd on a car that you cant really drive in the winter anyways.

As for usefullness, a Skyline is actually quite useless. Yes, it is fast, and problably makes a pretty good race car (if you want to spend $90,000 on a race car) but in terms of everyday driving, it is somewhat useless. You only have the ability to put 2 people comfortably, with another 2 smaller people. It is problably nauseating to drive in the city with potholes, and its problably very hard to drive in the winter. Your not going to impress anyone when you show up to a meeting in a Nissan, and really the only place where the extra speed is going to help you is to cut down the time on long trips, but really, you would have to be stupid to go anywhere near the 150mph top speed of the Skyline on a consistent rate, so really the advantage in top speed is nullified. The only real advantage for a Skyline would be the fun to drive factor, which of course the Skyline wins hands down, but is it worth it to give up all the pros of the escalade, and an extra $35,000 for the fun to drive factor? I dont think so, but evidently you do.

So in conclusion, your car is an overpriced, small, uncomfortable, unsafe (in relation to the escalade), and useless 4x4 that doesnt do what 4x4s are supposed to do.