The Disco is on a shorter wheelbase and has heavier suspension in the rear (or feels like it). The seats are not as comfortable, but then it depends on how long you intend to sit in them. They have less room for second row passengers. If it is a 7 seater, the seats in the rear are pretty much useless except for small kids.
Check if it has Active Cornering Enhancement (ACE) fitted and if so, that it is working. If it is, they corner like they are on rails.
It won’t matter if it is diesel or petrol, then key is how well it has been maintained. Regular servicing is a key to both. The auto trans is basically the same as the P38 and the manual is the R380 which is a very good box.
If it has been in a damp environment, check underneath for rust, as they are more rust prone than a P38. In a dry climate, this isn’t an issue.
I had 4 Disco 2s running around 75,000 km/year and they never put a foot wrong.
What would I rather drive? Probably the P38.
In answer to your question though, it really depends on what your truck is like and what the Disco is like. For the fun of it, if the Disco is in good, well maintained condition, go for it ….. but it isn’t a P38.