Am I crazy to sell this Yamaha

Impossible to answer, as it's up to YOU!

If you love Audio AND video, and want a nice solution for both audio amplification and audio decoding as well as video switching, you likely want to move to something with some of the latest tech.

My personal experience was that I found receivers to be wanting from a usability standpoint until component upconversion became available at my price range. I was happy! I could run all my inputs into my receiver and switch them from my receiver. My TV became nothing but a video monitor. Sweet!

Not long after that revolution, HDMI came along with the same thing. I had to spend $1500 to get 3 HDMI inputs and HDMI upconversion. But you can get all that for much cheaper.

There were a few bad things said about the 663. Mainly people complaining about it "clipping" blacker than black. I still don't see the concern there. I doubt most consumers will notice. There were some Yamaha receivers with a potential bug in the DTS-HD Master Audio decoder. That's more of an issue, but that may have been the 1800/2800 only. Be sure to check out the RX-V663 thread for any other gotchas.

The 663 seems to have less power than my RX-V657 did. The RX-V657 was more than enough power for my needs. I am an apartment dweller, but I still want decent power and I think the 657 had it. Hopefully the 663 didn't lose too much.

I would take lossless audio over even double the wattage(+3 DB). I traded my HTR-5790(Awesome amp. Lacked the features though) for the RX-V663 and I haven't regretted it a bit!

If one is satisfied with their current receiver, I would try using MC input for lossless before buying another receiver...

In regards to the doubling of wattage statement... I agree