They have more than one product. Which one, in your considered opinion, BLOWS?

I personally find the way 37signals promote themselves to be often distasteful, but I still pay for Backpack because it does what I need it to do, and almost nothing more.

Sure, some of the interface and features feel a bit dated, but no other similar service I've tried is as simple, elegant, and devoid of unnecessary, distracting, fiddly bullshit as Backpack. Honestly, is the fact that it's not a trend surfing web developer's wet dream preventing it from being a useful tool?