If they are the same price and it is one night, go for the value. We used Buena Vista Suites for one night at the start of our trip and it was fine. It was a tiny suite, nothing like a DVC suite. If you can get the value for the same price and be on property, I would go for that. The only benefit I can think of for Buena Vista is if you want the free breakfast.
You'd probably get better feedback in the Resorts forum. You're in the DVC forums, which are all Deluxe resorts, so you don't have an audience with experts on value accomodations.