Well, the one thing nobody here mentioned is the "Model Year-based depreciation". This is always one of the considerations when buying year-end. In theory, even if you buy a 2016 and a 2017 on the same day and put the same mileage on them, when you go to sell them, the 2017 will have less depreciation as a factor of age. This matters a lot less the longer you keep the vehicle.
At the end of the day, yes, it's nice to save some money, especially if you plan on keeping the vehicle long-term. But for us, it was most important to get the trim level, color, and equipment that we wanted.
We would have been happy to buy a 2016 Trail last month, and the dealers in our area were very willing to deal on them (although more so on their SR5's than their on their Trails, which were much scarcer), but we decided that we wanted a Magnetic Gray Trail w/ KDSS and NO sunroof, and it didn't appear that there were ANY 2016 MGM Trails left in SoCal (the last one we were aware of had been sold the week before -- DOH!). So we snapped up the dealer's first 2017 MGM TRD Off-Road (before it had even come off the truck), and still managed to negotiate a discount (although not as much of a discount as we would have gotten on existing 2016s).
FYI - the non-premium 2017 TRD Off-Road has a base price that's $420 higher than the 2016 Trail Edition, but comes with floor mats (which were always a $225 option on 2016s), a TRD Shift Knob, the Carbon Fiber Center Console, and the C-pillar badging. So depending upon your proclivities, that part may be a wash. Only other difference I can recall is the black accents on the wheels (instead of gray).
At the end of the day, if you get the truck you want, you will be happy...