No. Just no. I'm one of the biggest HD650 fanboys on this forum and that bolded statement is outrageous to me. The HD650 is often lauded as a headphone that scales very well to what it's plugged into. The HD800 is the same, but many times over. The HD650 at its best cannot hold a candle to the HD800 at it's worst.
Obscene hyperbole aside, I agree with your sentiment. I haven't put it to the test, but I'd imagine that an HD650 played through a TTVJ Pinnacle that's fed by the DCS Scarlatti would sound better than an HD800 straight out of a Nexus 4. However, in any reasonable comparison (and any I've actually heard), you're right. The HD800 is in a different league.