Okay, there's one in every crowd, and this time it's me.
I like the Pentax software and prefer it over Photoshop Elements 5 or Lightroom 2 beta. The only thing I can't do with PPB/PPL is selective editing (removing dust, dodge and burn, etc). For that, I use PSE5. However, PPL gives me better raw conversions, I can correct a variety of lens distortions, I can filter noise, I can save settings for individual files for later processing, or for applying to other files. And it's definitely quicker than the Adobe products (though, to be fair, Adobe is not about speed). Plus, with a large/wide screen monitor, or two monitors, PPL is very easy to navigate (need the room to spread out the menus you want open).
I came to this conclusion after I was forced to use the Pentax software while waiting for Adobe Camera Raw to add support for the then new K100D. Once I got over the learning curve, I found that I preferred PPL to PSE, and that didn't change from playing with Lightroom.
I realize the OP was commenting on PPB specifically (since he shoots jpeg exclusively). I mainly use PPB as a gateway to PPL, so I don't spend a lot of time there. However, I do find it quick to get around in. Sounds like there are limitations that I haven't run into yet, though.