I didn't do very well on the Safari, but that's mainly because I wasn't shooting in shutter priority mode, and the speeds were too slow. It was also later in the day and not as bright.
Here's a shot maxed out at 200mm... not quite as sharp as it should be (I think the focus was a hair off), but nice 'n' colorful.
And here's one more in the middle, 138mm.
Another, 125mm: (I don't know why these are missing exif data, they are there in my gallery in the full-size versions... something is screwy with the resizing. One more thing for me to work on...)
Here's a few WDW examples. They'll be even better when I finish redoing them all in Lightroom.

Yes, I know that a couple are at 700 pixels and one's at 1024; this was before I set 800 to my minimum in my gallery and I wanted to least one to show some extra detail.
Here's one of my Safari shots... 180mm, a relatively slow AF system (my DL has a simpler and slower AF than other Pentaxes), and not shooting in shutter priority meant that it's not as sharp as it should be. 1/180th second, F5.6, and ISO 200.
Don't let anyone tell you that you can't do short DoF with F5.6.

It helps that it's at 200mm...
All in all, it's a really nice little lens and certainly worth the low price. Stick it on your K100D it'll even be stabilized, and think about all the money you'll save over the C/N stabilized lenses of similar focal length.

(OK, that's not really a fair comparison, but what the hey!) It's small size and weight also make it a great companion to the kit lens. It's hard to go wrong with the combination of the two, plus a 50mm F1.4 for low-light.