Having owned a few discos and a few fenders, and a few series landies come to think of it, I don't think there's much to separate any of them in terms of ability. Choice of tyres would have a bigger effect than choice of vehicle most of the time. It all comes down to what you actually use it for and what you want it to do for you, and how much time you want to spend welding it every year for the MOT. Obviously I'm talking about older vehicles here if I could afford a new one that would be a different matter. Discos are great on the road, great for towing, generally reliable so long as you don't count the little niggles and wear and tear, but they rust like buggery and for me long term ownership of an older disco is out for that reason. I just can't be arsed with it. Defenders on the other hand are a lot easier to keep relatively rust free, simply because al the vulnerable bits are accesible for a good jetwashing and you can see problems before they become big problems. Also there are less annoying electrical bits to **** you around. I don't generally do serious offroading like p&p stuff, just some laning and what the landy was built for, ie farm type work and some fairly strenuous towing, but to be honest for local work and dragging a heavy trailer across muddy fields my series 3 109 wins hands down.