I like compact lenses as much as anyone else, but in my experience, most lenses I have are not that compact. Why? They are better or offer thing that I need/like. I do have a CV 15M and I like it. I also have CV 35P and CV 40/1.4 - also small and nice. I have tried CV 25M, 21, 35PII, CV 15LTM and sold them all. For me - it's all about what that lens will deliver. After trying several 21mm lenses (3 copies of CV 21 alone, as well as others), I now have a ZM 21/2.8 and I think it's the best 21mm lens out there other than Summilux 21/1.4 (which I have not tried, but I assume it's better). ZM 21/2.8 is larger, but it's much much better. My best 35mm lenses are largish too - M-Hexanon 35/2 and CV 35/1.2. 50's - well I have too many of those, but best are largish - M-Hexanons 2.0 and 1.2. I dont know if it's the small size that limits some lenses, but whatever it is - I wouldnt buy a lens based on size alone. Yes, I'm glad that Cosina offers those choices too - it's fun to try thier lenses and many are very good and dont cost too much. I'd love them even more if they performed like my other - bigger lenses, though.