Well, I have done both. I have rented points at BCV from a DVC owner, but also have stayed onsite at AKL, WL, the Swan, OKW (booked through CRO for that trip before learning about renting points), and CBR. I have loved all of my WDW trips, and cannot really say that one over another has been better (although I wouldn't probably stay at CBR again).
I do think that renting points is a great way to stay in more deluxe accomodations for less. I know that the DVC properties are considered home-away-from-home properties, but several are directly attached to deluxe properties, so you have all of those additional amenities. I just can't see paying to stay at the BC, even with a code, and paying those high rates. I was able to stay in a studio for a week, averaging $139/night ($9 per point and no tax). I could never have stayed in a standard room at the BC for that rate.
Sometimes you can get really great rates at AKL and WL, making a stay comparable to renting points in a studio. But, if you really want to stay at one of the resorts that has higher nightly rates (like BW or BC), then renting points is the best way to go, IMHO.
One thing to factor into your decision would be your desire for housekeeping services. They are not daily at the DVC resorts unless you pay an additional fee. When we stayed at BCV, I didn't mind having a cleaning once every three days, and tidying up myself inbetween, but others may feel differently.