I, personally, prefer BWV, but that's just me. I've always thought the boat ride to MK from VWL was overrated, but the bus is a really quick trip. I've had bad experiences at VWL when it comes to their transportation, so I would choose BWV based on that.
Pretty much I prefer the BWV as a resort overall, I like the restaurants better, the pool, the rooms seem bigger (are they?), the themeing of the BWVs is also more to my liking.