I haven't done any comparisons (use the 4896 here), but I believe the main difference is the PulsarMixer doesn't do the autorouting... I might be wrong though.
I asked this same question a while back and received no response.
They look the same to me. I tried the Pulsar Mixer and ran into problems but I don't remember what the problem was off-hand. As far as I am concerned, they are both buggy under SFP.