I can say that I have the Componon-s 100/5.6 for smaller enlargements of 6x6 and 6x4.5 and it is fantastic!! For larger enlargements I recently purchased a Rodenstock Rodogon APO (Non-N) 80/4 and it is incredibly sharp! For 35mm I use a 50/2.8 Nikkor that is fantastic too! Basically you have to buy and try. Enlarging lenses are strange beasts, some get bad copies of certain lenses, while others report they are great. Once you get a good lens never let go of it.