I would think that the Studio 100 is not more difficult to drive than the B&W703. As others have said, separates are better but I know for a fact even a RX-V2400 could do very well with the Studio 100. The 4306, or even a 3806 should give you enough power. Again, more power is better, the question is whether you could hear the difference in your listening environment. If you like the Studio, and want to forget about the 703, go and listen to the Signatures. Otherwise, don't write off the 703 too soon.