I traded a 4th Gen V8 Limited for a 5th SR5 and didn't regret it at all. After an unfortunate mid-intersection rendezvous with another motorist incapable of distinguishing stop from go, I got another 5th Gen (aTE this time). As much as I liked the SR5, I like the TE even more and could probably also be equally happy with a 5th Limited.
What I miss about the 4th Gen: the V8 torque and that is all. Although, while I miss it, it isn't that big of a deal.
What I like about the 5th Gen: usable space and overall comfort (esp 2nd row), climate control knobs and dash layout, off road handling, body styling (some will howl at this). The V6 has been more than ample for me (having said that, I don't tow).
Inquires like yours are more than reasonable, but sometimes stir up a "mine is better" pissing match here. I offer my opinion only because I have owned three 4Runners (a 4th and two 5ths).