[MENTION=6528]elemint[/MENTION] I recently just went through the purchasing process. I too came from a 3rd gen 2002 sr5.
In my opinion, when I test drove the 2016 sr5, it really reminded me of my 3rd gen. The way it took bumps and the steering response etc. it was a little smoother with a little less body roll. But when I drove the 2016 limited and trail with KDSS that's when I noticed a difference.
They handle better with less roll and seem more stable at higher speeds. The suspension was much smoother too. The limited actually felt kind of like a luxury car. For what it's worth I ended up getting the trail premium with kdss. I felt it handled and drove very well and I liked the exterior look better than the limited.
Is it a night and day improvement over my 3rd gen? Not really. It is better, and newer, but I don't feel it's like going from a civic to an NSX in terms of handling, but I'm happy with the upgrade.
But again, this is just my opinion