rotel rsp976 or rsp980 advice please

Hi Folks,

Last year I made the big leap from a yamaha surround receiver to old rotel separates. I also jumped from Boston bookshelf speakers to a DIY kit from GR Research plus a subwoofer and I've been very pleased with the results.

I primarily built the system for music, but I also run my dvd, tv and vcr through the system for 2.1 reproduction. I'm finding the need for a center channel speaker so dialogue can come out of the center rather than the speaker I'm sitting closest to, so here are a couple of questions:

1) I currently run a rsp980 (pro logic, not digital) processor through a rb980bx power amp. I'm very happy with the sound and run music through the 2 channel setting, with a sub cable going from "sub out" to powered subwoofer.

2) Our local craigslist has an rsp976 for sale at a very low price. It is digital, so I could connect my dvd player with optical out rather than rca.

-- does anyone know if the RSP976 is a step down in quality from the 980? I started with a rsp960 and found the 980 to be a marked improvement. I love the pro logic units because of their low resale value relative to sound quality. They also offer video switching which is convenient for my video setup.

here are my questions:

-- can the 980 with pro logic do a true center channel?

-- I currently use the dvd player for cd reproduction. will optical out sound better than rca out? (I plan to eventually buy a dedicated cd player.)

thanks for any feedback and suggestions

Steve