Ok, i'll give you an opinion since i own a MKII as well.
First off, ive bought it when it just came out, so was using it with a optoma hd20 (720p), at the time i was happy with it as i loved a scope screen.
I then had a benq w5000 (1080p) and used it with that projector.
I started noticing things i didnt like with that lens, mostly softening of the image when in the light path, light spillage.(the pincusion i expected) vs not using it.
I didnt have much choice as i couldnt zoom with that projector as it didnt have enough zoom.
I then upgraded to the epson 6010 due to 3D etc.
I now dont use the MKII lens with this projector as i find zooming much better and cleaner/sharper/nicer, no pincusion is a great bonus too, no light spills on the sides etc.
It is an old lens so cant expect it to be as good as the newer lenses out now( even tho i havent looked at any since i started doing zoom) and was a fair bit cheaper then the current crop.
If i had the hw50, i would zoom.(my ceiling is low that i can reach it easily), but i dont know how good the cinevista is so i cant really comment on that or compare it to the MKII.
If the cinevista had no noticeable picture loss/softening, no side spills i would consider it.
Have you tried zooming? do you find your MKII very soft and the other issue's i mentioned?
Edited by MAZMAN808 - 7/10/13 at 3:19am