The Samsung and Panasonic glasses performed about the same, although if we had to pick one based on picture quality alone it would be these Panasonics.
To compare the two glasses we used the movie "Hugo" as the opening five minutes make an excellent 3D test. We compared both manufacturers glasses on both a Panasonic TC-P55ST50 and a Samsung PN50E8000, both set to the default Cinema modes for 3D.
Switching quickly between the two glasses there is a slight but noticeable difference in black levels. The image viewed through the Panasonic glasses seemed just a bit darker on the screens of both TVs. We're not sure if this difference is caused by the lenses themselves or simply by the Panasonic's fit--the more closed design blocks out more ambient light even in our completely dark room.
There was almost no difference in color between the two sets of glasses, and the ghostly outlines of crosstalk appeared identical as well. Both varied depending on which TV we watched--for the record the Samsung was superior in both areas--but the glasses had a negligible impact.