One of the reasons why I traded in the Tacoma was an occasional need for a third row. It was not the main reason, but a viable reason nonetheless. I figured it would be an emergency use only, shove the kid(s) back there when family is visiting type of thing. There’s more room back there than I thought.
To be fair, it is not an easy row to get into. While it is accessible from the driver’s side, it’s far easier from the passenger side. The passenger side middle row seat can slide all of the way forward flush against the front seat (drivers side moves only half as far forward), giving more room to step in. I’d recommend your third row passengers be limber, so no “fluffy” grandmas should ride back there.
There’s actually a decent amount of legroom. Even more so if you don’t move the second row all of the way back (that’s one of those neat features I’m sure I’ll seldom use, the adjustable fore/aft second row, but I think it’s kind of cool to have). I sat back there (6’4”) and my legs were actually fine.
Headroom, on the other hand...well, I’d need to be headless for me to fit there comfortably. My son (9) has plenty of room, as did my wife (5’2”). It was tight, but doable for the billet kid we have with us this year (5’10’). That should make the third row viable for my son well into his teen years. Looking at the stats, Toyota claims rear headroom at 34.3” for the third row, a little over 4” shy of front seat headroom.
When not in use, the seats fold flat. One compromise with the third row equipped 4Runner vs the standard 2 row, the second row seats fold forward (meaning not the typical tumble forward 2 rows where you flip up the seat bottom toward the front, and then fold the seat back down) thus not giving a completely flat cargo area. A bonus (other than having the third row), is that since the second row is adjustable, you can slide the seats forward if you need an extra 6-9” of linear cargo space, and still carry a passenger.
Of course, when in use, there’s basically zero cargo space. A handful of lightly packed grocery bags, laptop bag is all that’s fitting back there.
All in all, I’m glad we have the third row...I just wish Toyota offered it in the Off Road or Pro.