I had an '03 Tacoma before my current '07 4R. That came with BFG Rugged Trails, which rode well, but were kind of a glorified street tire. I replaced them with Firestone Destination AT's. They improved the ride and grip in all terrains dramatically, and actually were quieter than the Rugged Trails.
When I bought the 4R, it had 39k on it, with the original Dunlops. Based on the depth of tread remaining, I estimated I could get 15K out of them still. After a month of driving the vehicle, I'd definitely picked up on how vague the 4R felt, especially compared to the Tacoma. I had issues with the traction control coming on making turns in the rain, and I'm not a wild driver. After 2 months with the Dunlops, I'd had enough, and bought my Revo's. It's completely changed the handling of the vehicle for the better. I think the Dunlops are a poor choice for a vehicle that expensive; ironically, the sales manager said the same thing. His Sequoia had the same tires, and he replaced them prematurely for the same reason. They offered to put new tires on for me, or discount the cost of tires from the selling price (or so they phrased it). I opted for the discount, so I could take some time to research what I wanted.
I think my experience is a similar sentiment to others on this forum, even those doing mild off-roading.