I have close to the same setup: DA50ES receiver (I had a 925 for a couple weeks and exchanged it, definately a nice step up... except for the hideous remote!), DVP-550S DVD player, and I just bought a CX-300. I also use a pronto to control it all.

Anyways, no problems to report between the receiver and DVD, that all works beautifully.

The CX-300, I'm not so sure about yet. I dragged the hideous 50ES remote out of the closet to test it out, and it comes so close to working, but then relegates itself back to 'useless' status. The problem is that disk numbers over 200 confuse the stupid thing. Back into the closet! I'd be interested to hear if the 935 has an upgraded remote that can handle 300 (or 600? Mega-control?) disks.

So, we'll have to see about the 300... it just has a ton of little problems that bug me, but that's pretty typical of Sony stuff in my experience. Why only 13 characters for memos? Why can you only chain 2 players together? Why can't you chain them using TOSLINK instead of analog? Why can't you even switch the display to 'track time remaining'? Why doesn't it sort things correctly when you're doing a 'memo search'??? Argh!

Maybe I'll check out the ES models to see if they do any better, but given that I need 2 of them to hold all of my disks, ES is a bit pricey... Maybe I'll just go back to the old trusty (CDP-C545) 5-disk player :(

I'll second the recommendation for the pronto though. It's the first remote I've had that let me put all the others in the closet...