I've tested it extensively against the V3 and the ASPH 28mm. Corner to corner this V4 is noticeably better than the other two. It is, in my opinion, the best of all Leica 2.8 28mm lenses. I have no experience with the summicron.
Includes original hood, hood cap, leather case, and generic rear cap. Can include high quality B+W UV filter for $20.
Price is U$1090 delivered anywhere in the CONUS. Would appreciate it if paid via paypal gift to save on fees and happy to provide references upon request.
Any questions just ask