While I really do love the AMT Vans, the MPC ones where way ahead in the detail department. Full interiors and more outside accessories, plus the 4X4 version of the Ford van where awesome.
In my opinion, the MPC Vans where #1, then AMT Vans and then dead last, Revell Vans. Monogram are honorable mention because of them being 1/24 and decently shaped.