on the lower end i may agree, but once you hit the higher end, i doubt there is much difference. caps are cheap compared to the other parts
$700 is not high end. In the under $1000 range every Marantz receiver is better than the equivalent Denon. Audioholics did an article a while back where they opened a Marantz and the equivalent Denon and they were quite surprised what they found inside the units.