I was wondering if any Limited owners that have switched wheel size, could shed some light on the ride quality between the stock 20 inch wheels vs. 17 inch wheels. And what about gas mileage? Thanks.

Well I probably have a different scenerio than what you have in mind but here are my thoughts. I have the stock 20" rims and tires for summer use and 17" rims with Nokia Hakka's for the winter. When I put the 20" back on this spring I felt that the gas milage and ride quality was better. I attribute this more towards the difference in tires than the difference in rim size. The stock 20" are smoother will less rolling resistance than the snow tires. I think the choice of rubber would be more important than the rim size. If you are looking at something like an all terrain I would expect the ride will be different and the mileage less than the stock tires. I don't know how a 20" AT tire will compare to a 17" AT tire. Maybe someone else has tried both and can comment.

20 in wheels usually result in getting a tire with less sidewall and therefore less lateral sway/bounce, this is readily evident in a 20x9 wheel. I'm still on the stock 17s for the TE and will be making the move up to 20's in a couple months. One for looks, and 2 for a more planted feel.

True, but 20's with a lower profile tire will give you a rougher ride. The bigger sidewall on the 17's also helps absorb the bumps and pot holes.

So you have 2 choices. A smoother ride with worse handling (17" rims) or a rougher rider with better handling (20" rims)

After switching to 17's with more aggressive tires (than stock), I have zero regrets. The mileage overall might be 1 mpg less (due to taller more aggressive tires). The handling may be slightly "worse" with the taller sidewalls and more aggressive tread, but I am still happy in that area. I'm sure the taller sidewalls do absorb road imperfections (potholes, etc.) better than the stock 20's. Overall, I'm very happy with 17's and it's nice to have many tire choices now.

In regards to ride quality with any tire17 or 20, you've got to consider the load rating of each. A load e 17 may be just as rough as any c rated 20.

Not to hijack this thread but, will you be selling the OEM 17" Trail wheels ? If so, where are you located ?
Thanks

Given the same tires would the 17 still be a bit mushy?

I switched to 17's (from a 2014 TE) on my 4wd LE a couple weeks ago and also have no regrets. I was sick of looking at the skinny tires on my LE and now have AT tires size 265 70 17. I feel that turns are much more stable with more rubber touching the road and bumps are less noticeable. Also, hardly any nose dive when braking. I still am surprised Toyota built a 4wd suv with 7 inch wide rims.

It kind of makes sense because most LEs 4x4 will more likely end up going to someone who prefer 'better' performance on snow/rain/dirt. 7 inch wide wheels will perform better than 8 inch wide wheels when it comes to not spinning on snow/rain/mud because there is more weight per inch touching the ground. Plus, although seemingly counterintuitive, LE buyers are more MPG conscious.

about sums it up.

I'm going to 17's shortly as well on my Limited... looking forward to a better selection of tires and a little better ride.

What he said, and I will add another point, if you do any off-road where you encounter rocks and scree, I think the higher side wall will protect the rims much better.
I had an Escalade at one point (please no flaming, it's a highway monster), and it had 22's. I can't compare the ride, but I did take it up a common trail in western CO, and let's just say " I wish I hadn't". There's just not enough rubber between the rim and the ground. I know this is intuitively obvious, but thought it needed to be said.

Put on 17" Michelin X-Ice Xi2's for winter in November and didn't notice any difference really. I was expecting a softer ride but couldn't notice any real difference. Gonna put the 20s back on within the next month so we'll see if I notice a difference going back.