We recently rented a Routan and I LOVED it!!! I told DH I want one:) We've also rented a Dodge Caravan and hated it. The 3rd row seat was tiny and very uncomfortable. The Routan's 3rd seat was actually fairly comfy, and roomier than the Caravan. It was also easier to get into the 3rd row seating of the Routan.
With a VW, repairs will generally be higher. My DH is/was a mechanic and told me that about all VW's. I don't remember what kind of gas mileage we got, but we were driving all over San Diego, even drove up to Disneyland, and didn't fill up very much. We didn't actually do the math. We were there 1 week, and I think stopped for a full tank only once, and a partial tank once the day before returning it (we pre-paid for them to fill it up when we returned it).
I loved the features, and the extra storage was awesome!!! We had 4 adults and 2 car seats in it and we were very comfortable, and we managed to get all of our luggage in the back just fine. I can't say that about the Caravan. We were squished and had to squeeze all of our luggage in the Caravan.
I also have looked at (but not used) the Sienna and Odyssey's. But, I would choose a Routan. Sadly, we don't have the money now, but I can dream! We've actually decided we would prefer a Suburban, as much as I said I never wanted one. But we want a 3rd child within the next couple years, and we have 2 dogs. A suburban will be more comfortable for road trips (we do a 6 hour trip a few times a year, so we have to think about that). Right now I have an older minivan ('94), that I actually love. It's very roomy and comfortable. We've done a lot of research into what we are getting next.