I've got a 2005 V8 sport that I've been using to pull my boat for the past few years. Just put a new Hidden Hitch on it actually because in Canada the V8's come with the v6 hitch. Anyway....
Crownline 206LS
Boat weighs 3800 lbs dry.(21 ft with platform)
Trailer is 1000-1200lbs.(tandem axle disc breaks)
Gas & gear approx 700lbs.
When the family goes camping we'll end up putting more weight in the boat now.
Never had a need for more power. Plenty of passing power when needed. To be fair, I never drive that fast while towing. I'll do 60 to 70 mph max on the highway except when I need to pass trucks and whatnot. I drive in forth 99.9% of the time. I know the boat is there but it doesn't "bother" the 4runner at all.
I had a reg cab '95 f150 with the inline 6 before I bout the 4runner. Family grew and I needed a spot to put a car seat. That truck pulled the boat. Barely.
I fell in love with my 4runner all over again the first time I pulled my boat. Going up hills, big ones, is a breeze. It won't pull like a big diesel pick up, because it isn't a big diesel pick up but if I needed to buy a new tow vehicle all over again it would be this truck. Hands down. No seconds thoughts.
Hope this helps if you have any specific questions I'll help where I can.