You can make more usable power with the tdi IMO also unless you go bonkers with the 4b, but then the usable rpm range goes out the window again. An ALH with an 11mm pump, 5x.010" nozzles, tune, supporting minor mods, and a 1756vk turbo will make 340lb/ft to the tires at 2100rpm and 209whp at 5100rpm. Show me any other diesel that can do that much in such a small package with that wide of a power band. If you're willing to delve inside the motor for a build (which is cheaper than rebuilding a 4B), you can up the turbo and nozzles and get into 450lb/ft 250whp range while still getting 90% of the mileage of a stocker. My 16:1 compression full race motor with compound turbos in an awd 3400lb wagon still gets 39mpg at 80mph.
As much variation as there appears to be between the castings of the various iterations of the tdi with regards to crank centering (re: Jimbote on tdiclub). My dream is that you would include a centering jig like Jimbote's, some good instructions on how to use a dial indicator to center it, and some way to lock it in once it is centered. But don't listen to me, I'm just dreamin'. I love the idea of diesel swapping minitruck yotas with tdis but am currently focused on the vehicle in my sig.
Jim is a good friend of mine actually! Why he ran into all the crank centering issues is because the particular adapter kit he used doesn't do dowel to dowel centering; it relies on bolts to center. Anyone in their right mind knows that's a terrible idea when it comes to centering something critical.
This is an ls to audi r8/gallardo trans adapter I helped design. Notice the dowel pin locations.