Worthwhile? Sure if when you listened to it did it made you happy. Does it have all the options you need/want? For $650, sounds like a fair price if the answer to both questions is yes.
If you haven't listened to it and are just buying based on specs and reviews, may I recommend you try to find time to audition it and possibly consider the Yamaha RX-V1600, Denon AVR-2307/2807?
Usually I do an initial audition of 2-3 receivers on the same setup (speakers, sources) with store equipment to make sure it performs at a minimum of requirements. Next, a specialty store will usually allow you to bring a receiver home (some may require a deposit/credit card info) to audition the receiver with your own system.
If you are buying at a Best Buy like store, obviously that isn't possible but they usually have a no hassle return policy. Look into it to make sure there isn't a restocking fee.
Even harder to do is buying online. Most people I know who went this route first audition at local stores.
FWIW, Pioneer Elite is generally well regarded for quality and sound. The Yamaha/Denon/Marantz/other options will all have similar specs but may just sound a little bit different in their own way which may, or may not, please you.