It's great to share opinions and compare kit and all that, but more importantly for me is my own trial and error.
I tested out some handheld exposures to see where I could get to a comfortable level without having to carry a tripod or even monopod.
Keeping ISO at 100 on my K10, I pushed this shot to 1 second and f9.
OK, admittedly, I wouldn't be making an A3 print out of it, but even at full size the photo isn't as blurred as one might expect.
Certainly doesn't look bad.
Therefore, I feel Pentax's SR is fine for me.
This was just a test shot, but I needed to be content in situations where I would be shooting at night knowing that I didn't want to take time setting up my tripod, and it wasn't always convenient lugging a tripod around in the busy streets of Tokyo.
I know the OP talks about SR being less effective with longer lenses, that may be the case.
But, like I said, for the lenses I use and situations I need, I've found Pentax SR more than acceptable.