I love my V8s. I have a 3.5 110 and a 3.5 130. Also a 4.6 Classic. I also have 2 200 Tdi Disco, a 200 Tdi 110 and just bought a 300 Tdi Disco.
The 130 is an expedition vehicle. The 110 Tdi has a rotten bulkhead, so all the mechanics is going to be transplanted into the 130 to make it more useable on a long run. I will get a longer range out of the fuel tank, and carrying spare fuel is safer. (btw, I was quoted about £1,000 to do the conversion)
Given the choice, I would have chosen a 200 Tdi engine. Why? It's simpler than the 300. The 300 has the serpintine belt with noisey tensioners, EGR systems, head gaskets failures, dog-leg gasket failures, etc. But the 200 just keeps going. And, in my experience, you sometimes get a good 300 engine, but most of the time they don't have as much poke as a 200.
And if I'm being really, really honest, they are just as quick as the V8s when you're moving. Not as quick from a standing start, but once rolling they pull well. Infact my Tdi 5 speed Defender will easily outrun my 4 speed with overdrive V8 110.