The 325 has been an incredible receiver. Lots of power, A/V connections, flexibility and the last black model before HK went to the silver/black combo. I actually had 9 speakers running off this thing once just to try out the 7.1 and multiroom at the same time with the help of an external 2 channel amp. And this HK weighs a hefty 40lbs.
The 573 is pretty basic compared to the HK but I got it for $99 after a nice Fry's sale and a $100 gift coupon. Its in the living room and its a simple unit for my friends to operate when we're watching TV, listening music, etc. Nowhere near the power or flexibility of the HK, even though its supposed to be 75 wpc but does everything I need.