Royce, I don't have any personal info to add, but you may not have seen that the 74TXVi will be reviewed in the October Sound&Vision and that the lab results are
up online . Also, besides the Audioholics review on the 4600,
Secrets has a rather thorough test, showing similar excellence(despite a couple of apparently obligatory "massmarket" comments by the reviewer). Both of these would appear to have more than enough power for almost any real-world use in the home, so as usual, decide on the basis of which features are more important to you, and price, of course.
