Some other things you should consider or be aware of:

The RX is monocoque (also called unibody or unitized) construction.  This
method generally provides a stiffer chassis for better handling, better
strength-to-weight ratio, and better crash protection.  Most modern
passenger cars are made this way, with the notable exception of the Ford
Crown Victoria.

The GX is a body-on-frame construction.  Trucks generally use this type of
construction because of greater overall payload and towing capacity and
strength where nimbleness is not a critical attribute.

Chassis type does not really affect ride quality and comfort.

In other words, the RX is more car-like and the GX is more truck-like.

The GX has a longer wheelbase than the RX.  All other things equal, a longer
wheelbase will give a more comfortable ride with less pitching (porpoising)
than the same vehicle with a shorter wheelbase.

I believe the tires on the GX are larger than on the RX and so will cost
more to replace.

Routine maintenance on the RX will be slightly less than on the GX but if
you plan to keep the vehicle for a long time (10+ years), then battery pack
replacement on the RX will eventually be required for the RX and not for the
GX.

You may wish to consider the conventional RX instead of the hybrid, unless
you want the extra performance the hybrid offers.

For 6,000 miles a year, my personal choice would be the GX.

I have had two RXs and one GX.  The two are night and day different.
The RX is a nice grocery getter Mom van.  The RX has a very nice soft
ride.  Easy to drive, not bad on fuel and not good at all in bad weather.

The GX is a serious luxury SUV.  It has high and low ranges, locking
differentials, adjustable ride height, adjustable ride stiffness and
more.  It will go on or off road with ease.  The drive train is much
stronger in ever respect.  The ride is excellent, but getting into and
out of does require the use of the built in running boards and sometime
the grab handles.  There is a lot of cargo room with the seats down.
The seats and a bit harder to stow than the RX.  It is a pig at the gas
pump!

If you are going to the store or taking the kids to school and that is
about it, but the RX.  If you want plow through snow with your $50K plus
 truck, get the GX.  Both are nice, over priced and very well supported
by an excellent dealer network.