IF towing matters, the tow rating difference between the LX and LC is over 1,000#. May not matter if you won't be towing or will be towing less then 6,000#. The 300# difference in vehicle weight does not account for the 1100# difference in tow rating. My speculation is that the AHC is the culprit. We tow a 6,000# trailer so it mattered to us - though I know people who use an LX570 to tow the same trailer and love it.
BTW, I'm with those who prefer manual tailgates and rear seats. I had the auto stuff on my Acura and on a smaller Lexus. I found it was too slow for me - and when I tried to "make it go faster" it would get angry and push back.
FWIW, I towed my 32 Intrepid on short (20 mile) trips around town with no problem multiple times with my old 2009 LX. The boat / trailer combo is around 12,000 lbs give or take.
I think the weak points on towing are the transmission and the brakes. The LX and the LC have built in trans coolers, and my trailer has brakes. Obviously, I would prefer to own a 2500 diesel pickup to tow the boat, but I don't have one. I never once had any issue with the AHC even with that heavy load / trailer. In fact, I loved being able to lift the truck up so it didn't get salt water on it when I was backing the boat down.
Toyota is super conservative on tow ratings. For instance, the 2008 LC was rated for 8,500 lbs. 2016 rated for 8,100. Same truck. 2008 Sequoia rated for 10,000. 2016 rated for 7,400. Same truck.
Finally, the tail gate being manual for me is exactly what you said. The auto ones are super slow, and they "get angry" if you push on them. Although on the LX there is a switch that totally disables the auto tailgate, and then its manual with no feedback.
I am wasting my Monday morning typing this instead of preparing for my tasks at work!