I think Landrover's do this to all of us who are smitten by them.
They all pretty much have a quite specific niche in the 4x4 market but they are all so good at both on road and off road, that it leaves you struggling to choose.
My first LR was a disco 300tdi, I felt like it was boring to drive so got rid of it for a series 3. Had that for a month or two before I found it unbearable as a daily drive, and went back to the disco. Then felt bored again, so went for an old MGB. Had that for a couple of months and then went back to a disco 300tdi once again. I've had this one for about 18 months now, and it's nothing of a chelsea tractor, nor does it scream of the traditional Landrover style. But it's big, reliable-ish, and it's good off road, (not quite as good as a 'fender).
To that end, it is quite a boring car to own, but at the same time, it is exactly what any land rover should be. A no-frills workhorse with a great off road pedigree. It's that very mindset that grounds me, every time I get the urge to change for something more fun or exiting, like a defender, or a L322. I think so many people buy Landrovers with their heart, and not with their mind.
If you're after a cheap car with easy and cheap maintenance, which is almost as good as a defender off road, almost as utilitarian, and almost as big inside, but without the constant worry of theft, then disco is the one for you. D2 or tdi is your choice. Obviously D2 still looks reasonably modern (although will begin to look very outdated within the next few years) and discovery tdi's look very dated already.