I ran across this site recently and found it contains useful eyepiece test results. Not sure yet how to navigate the site to reach all of the tests but here are a few to start:
http://www.astro-okulare.de/English/indexe.htm
http://www.astro-okulare.de/English/pentax/penxw5e.htm
http://www.astro-okulare.de/English/pentax/penxo5e.htm
Note -More eyepiece tests are listed in the German language site.
http://www.astro-okulare.de/English/indexe.htm
http://www.astro-okulare.de/English/pentax/penxw5e.htm
http://www.astro-okulare.de/English/pentax/penxo5e.htm
Note -More eyepiece tests are listed in the German language site.