Transits, in my experience, tend to be mechanically sound with long lasting reliable engines.
The main problem they have is rust. First thing I did when looking to buy was check the chassis and sub-frame. Surprisingly for a 20 year old Transit they were both in very good nick. That along with it driving very well, made up my mind.
Only other vans I have experience with are Mercedes, which I prefer, but they're more expensive all round.