Guess I don't get it.
What's the point of getting a 4 cyl if it's still got the slushbox behind it? With all that weight you've added on that thing is going to be as slow as molasses running uphill in January, and I'd be surprised if it gives you any improvement in MPG.
Now a 4 cyl/5 speed combo would make sense to me. But given how un-spectacular even the 3.4 is with an auto, I can only imagine that the 4 cyl/auto combo is much, much worse.
I guess its unique, if that's what you're going for, but I can't imagine that it performs any better or gets significantly better MPG than a standard DC 4x4 with the 3.4/auto combination.
I believe it gets about the same (comparing my pop's DC and my buddy's 3.4 auto 4Runner) MPG. While it's not as quick going uphill, with a loaded bed full of camping gear/wood, it get around the same. So you might get there a bit slower, but you still get there the same.
Less cylinders/easier to work on (no stupid intake manifold like the 3.4/3.0) and as long as you aren't trying to make it a zombie TEOTWAKI rig that can out run and out drive anything, you are good to go.
Oh, and it has a timing chain, unlike the v6's with timing belts.