A very good design which has poor execution and reliability. I don't understand why GM can't do better than this. Attractive design, good driving characteristics, roomy, fun to drive, economical and utilitarian. Poor quality components.
This is the 2nd Montana we've owned. The first (2000) we bought new and kept for 3 years (55k miles). We had no real problems.
In a budget crunch I bought a 1999 for $6,000 off EBay (High Mileage, $105,000). Overall, I'm happy. I paid so little for the van that the $3,000 in repairs have been worth it (we've put 50,000 miles on the van).
On the good side, the van has never left us stranded. On the bad side, there have been a lot of repairs. I have a lot of experience working on cars and have been able to identify most of the problems pretty readily.
This car's motor is challenging to work on. It's shoehorned into the engine compartment so that even routine maintenance is challenging. For instance, to change the rear three spark plugs, you must take the two front engine mounts apart and use a ratcheting strap to rotate the engine forward. Even then, they're very difficult to get to. With practice, it gets easier to work on, but you'll need a mechanic who has experience with these vans. Otherwise, the mechanic will likely become frustrated and not do a very good job.