Go for it! They've ironed out most problems and the new ones come with terrain response and rear diff-lock as well. Wading depth is deeper as well. There's nothing like it - it does everything well whether on or off-road and the TDV8 is a peach of an engine.
They still make the occasional lemon though but these are thankfully rare.
Rumour has it that a new model comes out in 2010, what is certain is that a new 5L V8 (more powerful and economical that the current 4.4) is coming soon.
If you want a stronger tyre than the road-biased one it will come with, you can get the new Pirelli Scorpion ATRs in correct sizes. This isn't as aggressive as a BFG A/T or General AT2, but much better on rough roads (and wet grass!) than the standard items because of its stronger sidewall and deeper tread.

