The new D10's work fine with all ReplayTV's, 5504 and up have gotten a software update so they support APG serial data and the older ones can be made to work with an adapter that's about $40 (w/shipping) I believe.
I have a old Sony B3 that works great via serial comms with my replay. It lacks some of the features of newer IRD's, but I always use the replay interfaces so it does not bother me. No digital out either, so its days are numbered. I have a Sony A50 that has all the bells and whistles but I have never been successful using the replay tv ir blasters to control the it.