With my 4Runner now, the cruise control is just not very pleasant unless on relatively flat roads. It is a big, heavy box that has just enough power. So anytime it is loaded or on a grade or has draggy things attached, it has no choice but to kick down to 4th or 3rd gear to maintain speed. And it doesn't want to just kick right back down after upshifting, so it holds that lower gear over the crest of a hill where I'd normally have let off the accelerator. The vehicle can't see that we are cresting a hill. It's much more pleasant to just drive without cruise control on anything hilly.
This is the main reason I welcome the turbo, the hybrid, and the 8AT. The engine can build boost to keep the exact same RPM and make more torque on small hills. The electric motor can kick in to give more power. The gear spacing gaps are going to be lower on the 8 speed, so it won't be as noticeable when the vehicle downshifts or upshifts by one gear. Being able to blend these three things will really improve the way the vehicle drives, IMO. Right now, gear and throttle (and to lessor degree, variable valve timing) are the only tools the 1GR and 5AT have to work with.
I'm honestly just worried about weight. The GX is 1000lbs heavier than my 4Runner. That's over 20% heavier. Hopefully a lot of that weight gain in the GX doesn't impact the LC. 5300lbs would be OK.