I asked around to some friends before buying a DVD, and was recommended the 550D multiple times. the higher end models only give you changer control (multiple dvd's/cd's) but since i already have a cd changer, i  didn't need to pay for that functionality. I have never had any issues with  audio track and video track being out of sync, in fact it has worked  perfectly. the remote control is intuitive, with multiple rewind and ff  speeds. The slow motion also has multiple speeds, so you can go frame by  frame with the jog function, or the system can move forward very very  slowly front or back. full features, digital menus, most of the controls  can also be done from the console of th machine itself. I play cd's in it  all the time as well. Optical jacks and svid and coax, really offer  flexibility when connecting to your stereo system.  I especially like the  built in dts decoding and dolby digital outputs. Very nice system!