purchasing a Tundra 4x4.. TRD off road special or not really?

What does it get you over the regular 4x4? Any years particular better than others? Im looking at the double cabs only and 5.7 specifically
Also when did the power sliding rear window become common? ( not the crewcab giant window)

Thanks

 

TRD Offroad is essentially a wheel and suspension package (and a plastic gas tank "skid"). If you are buying a decently high mileage truck the shocks probably need to be refreshed anyway and the previous owner might have also swapped wheels so...



Edit: pulled that image from a 2012 brochure but most of the info should basically remain the same for all 2nd gens... https://cdn.dealereprocess.org/cdn/brochures/toyota/2012-tundra.pdf