On the negative side the K-01 LCD is crap out in bright light, you either have to stand in the shade or get some sort of hood otherwise it becomes a point-n-shot-n-pray.
It's a great indoor camera or a well lit street camera at night.
I'm happy I bought one, the image IQ is excellent, the ergonomics are quirky but not uncomfortable at all for me. The button placement isn't as bad as some have said and it's pretty quick to learn to operate in full manual mode (which is how you can use the telephoto, fully manual with manual focus and focus peaking - much quicker than AF).
The rubber flappy door is irritating and slow, not sure what they were thinking there..
I had an *istDS since 2004, after a short learning curve I never found I missed not having SR. I quite often switch it off on my K-7 as I can get sharper pictures when it's off.
At the current sellout price, every PENTAX fan should have a K-01 in their kit, there's really no good reason not to