My wife has a 2018 4Runner Limited, and I recently bought a 2019 Tacoma TRD Off-Road Access Cab.
The 4R has a softer ride, softer brakes, and the transmission is more immediately responsive. The interior feels spacious. We took two friends on a week long trip with us and we had plenty of room for four adults. The 4R would really make a nice "overlander," to include drawers in back and a fridge as there is a lot of room behind the rear seats, and then a roof top tent or tow an off-road trailer. The Limited we have also is always in four-wheel full-time (unless put in part-time), which I have to say is just nice for wet roads where you wouldn’t use part-time. The ride is also a little quieter (no rear tire noise like with the Tacoma). The rear window that slides down is also nice to just reach in the back. I do find the seats although larger, less comfortable, and could use some more padding.
The Tacoma has better MPG (2 to 3), and well just having a truck bed is nice. It doesn’t matter what it is, can be dirty, you can trow it in the composite bed and who cares… later just wash it out. The bed has tie downs and options for racks. Payload is however low (1150#s on mine which double cabs have less). Of course, everything you put in the bed is subject to weather conditions. I can see why a lot of guys put roof top tents on Tacomas, as they don’t have to be up as higher. Plus, I’m considering a Four Wheel Camper “Project M” for it which is an option along with other camper tops. Also, the seating is lower to the floor then the 4R, which doesn’t bother me, but some people mention it. The ceiling and the door opening height is also less, which I'm 5' 11" and I feel like I have to duck my head a bit when getting in. I think if someone was well over 6', they would be too tall to sit and see out the windshield. I also really like my two-door access cab as I just don't need rear seats that just take up room (not to mention that I can't imagine adults traveling for long in the back seat of a double-cab Tacoma).
I honestly like both! They do feel like they’re both the "previous model" compared to competition, but both are solid and well built. The 4R's plus is the large rear seat, and well just a large interior, if that's part of your needs.