We rarely feature price so prominently in the opening paragraph of a review, but in this case it seems appropriate considering price is this product's main sticking point--or at least the one thing everybody seems to balk at when we mention it. And that's too bad, because the SoundDock Portable is an attractive iPod accessory. Available in black or white, it has nice clean lines, a nifty little hideaway dock that swivels open and closed when you press on one corner, a simple-to-use remote, an auxiliary input for connecting other portable devices, and decent performance. But tell someone it costs $400 (after they listen to it) and you'll get plenty of head shakes. And to be clear, that's a firm $400--you won't find this discounted at Amazon or Buy.com.
So, are you a sucker if you decide to buy this thing? Not exactly, but you sort of have to embrace the idea of overpaying for a product and not worrying about it. It helps that the SoundDock Portable is well-built. Pick it up and you'll notice that it's got a nice heft to it. Weighing a tad less than five pounds and measuring 6.75 inches tall, 12 inches wide, and just more than 4 inches deep, it's almost the perfect size: light enough to carry around but heavy enough to make you feel that it's made up of quality components.
There are smaller--and much less expensive--portable iPod speaker options out there; the Altec Lansing iM600 ($120 street) and the Logitech mm50 (soon to be replaced by the Logitech Pure-Fi Anywhere) come to mind. Those flatter models are easier to pack in a suitcase, while the fatter Bose is probably better-suited to being moved from room to room at home (or out on the deck). Its bigger size means it'll offer a richer sound, with more clarity and better bass--and play flat-out louder, too. While the Altec Lansing's built-in rechargeable battery is rated at 7 hours and the Logitech's at 10, the Bose's is rated at just 3 hours--though Bose says you'll get several hours more if you keep the volume at mid to lower levels. As for the SoundDock Portable's battery, we did appreciate that it's detachable and replaceable, though they'll cost a steep $89. (Thankfully, you should get several years of use before needing a replacement.)

It's worth mentioning that when your iPod is docked and the SoundDock isn't plugged in, its battery not only powers the speaker but keeps your iPod charged at the same time. That's not necessarily a bad thing, but chances are the speaker's going to lose its charge before your iPod does, so it might not be the most efficient use of power.
A couple of other nitpicks: a lot of today's iPod speaker systems have built-in AM/FM radios. This one doesn't. Also, you won't find any bass and treble controls on the unit or its remote. If you want to play around with the EQ settings on your iPod, you can (we turned the EQ to "off" because any other setting seemed to have an adverse effect on the sound), but the speaker's settings are fixed and you get the impression that the speaker is processing/filtering your music to optimize it for the speaker's frequency range. That's mostly a good thing, but some audio purists might find the lack of flexible controls unsettling.