Meredyth Didier wrote an excellent review of the Bose SoundDock in which she compared the SoundDock to two other portable speaker systems that she previously reviewed: the Altec Lansing INMOTION Portable Speaker System and the Sony SRS-T55 Folding Travel Speaker. According to her review:

I tested the sound using an audiobook, classical and techno music and the tone range is exceptional on all tested types of audio for all-in-one device with no speaker separation. These speakers are significantly better in all categories than either of my two existing iPod setups.

Of course it should be pointed out that the SoundDock costs three times as much as the inMotion speaker system and nine times as much as the SRS-T55.

I bought my wife the inMotion speaker system mainly because I thought it had the best bang for the buck and was the most portable of the iPod-specific speaker systems. I agree that people who are planning to keep their speaker system in one location and who are interested in the best audio response available in the class would probably prefer the Bose SoundDock. I think these two products deserve to dominate the iPod speaker aftermarket.