I haven't shot a whole lot with the 25mm photar, nor made formal comparisons to the other macro lenses I've used which are M-componons and schneider makro symmars. However my impression is that overall its a very high quality lens with good sharpness and color rendition. One big advantage of the photars is that they are faster than the M-componons or zeiss luminars. This makes it much easier to focus. It also seems that the photars are more compact than other makes (depending on what its mounted to and if you use the cone shaped adapter) and that provides more lighting options since you can use front lighting where other lenses would obscure the subject. The leica 12mm f/1.9 photar is also excellent.
forgot to also mention another nice feature of the leitz photars is the aperture which stays rounded throughout the range from wide open to all the way stopped down.
I've got the Minolta versions of both 12mm and 25mm. Exceptional optics. Supposedly Minolta made them made with Leica's help back when the two companies were friendly. Love to know more if their collaboration on the pair is popular myth or fact ?
Here's some sample images taken with the 25mm photar. These are close ups of a small pheasant feather. The first image showing a portion of the feather (approx 3 cm across the frame) is taken with the Rollei/schneider 150mm apo macro lens. I did not note the aperture.
http://www.eh21.com/Forum/GH-150mmAPO--012978.jpg
Then two higher magnification images taken with the 25mm photar. These are full frame reduced to 20% - sorry I don't have time to generate 100% crops right now.
My experience with the Leica R glass is the minolta made lenses are not the equal of the German made ones. This may or may not be true with other lenses such as the photars however.
