I think you'll definitely get the itch once you have a receiver that's not creating the distortion you mentioned. The VP150 will stand out and the Yamaha's will start to limp along behind
HT gear is an addictive hobby. The good news is you have a great center channel to start with and you'll love the M60's when you're ready. When the time is right, get some QS8's and start saving up for an EP500 to complete the experience
Every time I sit down to a movie I remember how lucky I am to have the same setup.