Yesterday I received the new
Pentax 18-270mm (as well as the new Q adapter) and I will soon be posting a hands-on video with both.
For now, I'd like to offer some first impressions of the lens. To start off, here are the pros:
1. the AF is reasonably fast overall, and there is no hunting on the K-5 IIs (then again, if you have a IIs you likely won't be getting this lens)
2. the build quality is good, and there appears to be no zoom creep (the 18-135mm is a little worse in this respect)
3. it delivers decent sharpness overall
And the cons:
1. no quick-shift. this is extremely annoying, because it means you have to flip the switch on the lens to get MF.
2. in dim/indoor light, it's really bad for shooting stuff that's moves
3. vignetting is really bad at 135mm and beyond (need to be shooting at F11 or above at 270mm). below 135mm you'll be fine if you stop down to F8
4. Bokeh is rather ugly
Strangely, at 55mm, Av mode won't let you select anything faster than F5.6, so it'll feel just like the kit.
And for the record, it's not even made by Pentax, because it says "made in china" on the back
Bottom line: really no reason to get this lens over the 18-135mm unless you just want to have a single lens for everything.