When looking for my first 8 I saw the 3.0tdi 4.0tdi and the 4.2tdi the 4.2 was out of my price range and I didn't look into it properly and thought a 4.0tdi was in the £400+ tax bracket

so I ended up with a 3.0tdi, now can you guys talk me out of not wanting a 4.0tdi, I'm a bugger for changing cars, my e39 didn't last 12 months.
Whilst reading up about them before my purchase I was under the impression that the 4.0tdi had some archaic fuel injection but it uses similar 1600 bar piezo injectors like the 3.0tdi, if I'd of known all this before hand I'd of gone out and gotten the 4.0 esp as iv always wanted a v8 to tick that box and the MPG isn't a million miles away from each other, oh and the 4.0tdi is usually better specced, any 4.0 tdi owners here that can give me there real world opinion? I like the 3.0tdi but I think I'm pining for that extra power the 4.0tdi gives