I have both woodgrain pairs, and I would say that the woodgrain print is much nicer on the Montefrio. It looks much more realistic, and the print transfer was executed better. However, the fit of the Montefrio isn't that great, and they make you look like a porn director from the 70's.
The JS woodgrain print seems to vary a lot between individual frames. I originally ordered my pair online, and they had little areas where the print didn't transfer to the frame; just small defects, but it bothered me. I ended up exchanging them at the O Store and after digging through all the pairs they had in stock, I was able to find one that was near perfect.
Mine looks like a good transfer all over. Haven't seen the montefrio's in person. I am interested in getting one to add to the collection at some point.