Mike, all of the major brand HT receivers are competently designed and add no audible sound coloration during the basic amplification process. The most important factor in choosing one these days is the auto calibration/room equalization processing it uses, which does audibly affect the sound when it's applied. Your 630 has auto calibration but not equalization, but the current HKs have the EZSet/EQ which does both. On this all-important point, however, I use and suggest a unit having Audyssey MultEQ for anyone considering a new receiver at this time.
Notably, the Denon and Onkyo models have selected Audyssey rather than their previous proprietary systems and my suggestion to fit your needs is the Onkyo 809 factory refurb available for about $600 from Accessories4less
here . These units which have been refurbished by the factory should be at least as reliable as a brand-new one, as many users(including me)have found.
