Frankly while a good alternative, in my opinion does not cut it. Even with my tiny 35/3.5 uncoated Elmar mounted in my M2, which practically flush to the body and does not need extension, its still bulkier and heavier than my CL with 40/2 Summicron and not as pocketable in a light jacket pocket.
Another alternative but completely different is a Contax T2. Compact, pocketable and a top class performer. 38/2.8 Sonnar lens. About $300-350 lately.