I believe you are on the right track Ferguson. A number of the receivers in the HTR line are exactly the same as those in the RX-V line...just rebadged for a different "class" of retailers (in other words their high end retailers get the RX-V line while the box stores/low end get the HTR line even if they are identical).
It appears the HTR-5890 is exactly the same as the RX-V1600. The RX-V1500 would be very similar to the just recently discontinued HTR-5790.
By the way if you are interested in the RX-V1500, you may wish to check out here -
The Audioshop - Ottawa. They are clearing out the 1500 & 2500 receivers at some decent prices. While i personally have not purchased anything from them before, I've heard of many others who have had good experiences with them.
