Hey there. I have the DTT3500 series. I LOVE them! I also own the SBLive! Platinum 5.1 as well. They make an excellent combo. I would go with the newer 3500 for several reasons. First, when you use SPDIF to get Dolby Digital with your DVDROM, the Windows volume has no control over how loud your speakers get. Therefore, if you watch DVDs a fair amount of distance away from your computer screen, you would have to walk up to your Cambridge SoundWorks receiver unit and control the volume from there. The DTT3500s have a remote, from which you can tune the volume, which makes it much easier to tune the volume. That was the main reason for my buying the DTT3500s, but everyone has a different setup. Also, one more thing to note, the DTT3500s have a larger subwoofer, so I would assume the bass hits lower on the DTT3500s. All I can say is D A M N! They work excellent and I love them.