Got mine one week ago (the packaging of this lens is top) and I was finally able to go out this afternoon and give it a try on my K3.
It is a good opportunity to get some digital work done as I a mostly analog recently.
The look I get from this lens is for sure different from the other lenses (I have only recent Pentax lenses) and I must admit I like the results.
For sure I will need some practice to find the good subjects to shoot with this one (just like it is the case for any other lens).
Here are some examples I have put on my Flickr account:
Lomography Daguerreotype | Flickr
The results can be very soft (with the widest aperture) or very sharp (as soon as you get wider).
You can get some 'interesting' bookeh depending on the 'metal plates' you insert to get your aperture.
Plenty of room to experiment and not knowing what you will get as final result is something that pleases me.