It's a very good question, but i'm afraid one I can't answer - we haven't yet done upscaler comparisons between receivers and players for the mag. I'm sure it's something one of our test guys has tinkered with, however, so will ask their opinion on Monday.
Personally I feel the receiver angle is the way forward - why just upscale DVDs when you can upscale everything? The difference it makes to SD TV, for example, is incredible.