Sony 9100ES, Oppo 103 105

Redoing home theater, I have the 9100ES and was wondering about the difference in sound quality, for DVD movies only in 5.1, between the Sony and the two Oppo's. Aerial 7b and CC3b front speakers. Thanks.
The Sony is a very good player. Since you are using it for 5.1 DVD movies, you most likely feed its signal into a multi-channel processor. In that case, you won't hear any difference at all. If I were you, I would save the money for something else.
I agree with Sidssp. I doubt you will notice any difference between the 2 if you are using it as a transport. There is one thing you may want to try. I had the 9000ES and had a very interesting experience with it. It took me a couple of weeks to figure it out, but what happened was it degraded the sound quality of my system when I was using other sources. When I removed it from my system, it went back to normal. You may want to try a power cord like a JPS Digital AC or a line conditioner that isolates each outlet. Even if the Sony is your only source, you could probably make it sound better with some power products. Try before you buy, though. I get everything like this from Cable Co first. That way I don't waste money.
Thanks, Just what I wanted to hear, as the Sony is working great and is so easy to use.
Well, let's not forget that the Oppos also offer many more format playback options. I realize that the OP asked about DVD only. But chances are that he will eventually want to explore the rapidly increasing world of Bluray audio and video. The Sony cannot do this.

Additionally, the Oppos will also allow the playback of DVD-Audio discs, the Sony cannot. And even more: the Oppos will also connect to a home network and/or the internet. This opens up a whole new world of music sources for him to explore. The Sony cannot do this.

And, in the case of the Oppo 105, this unit can operate as a stand-alone, multi-channel DAC that uses the ESS Sabre DAC chips, regarded by many as the best in the world.

Plus Oppo's customer service is head and shoulders above Sony's in terms of responsiveness and overall customer satisfaction. And Oppo are constantly updating even their out of production units with new features and capabilities.

All in all, the Oppos are *much* more versatile machines and will future-proof his system for years to come...

Though at this time I am not interested in those other features, if I want blu ray, is there a difference between the 103 and 105 when used for 5.1 channel movies only? Processor is Sunfire TGP-5.