What does one really sacrifice in using this shorter (than 300mm) focal length? I would be making maximum 20 x 24 enlargements of 8x10 negs. Am I going to notice reduced edge performance? I have used a 135 componon S for 5x 4 and have noticed no difference between this and a 150 rodagon on the print (up to 20 x 16). I realise that at huge enlargements, the shorter focal length may not have the coverage, but at what sort of enlargement might this come into play.
The added bonus of 240 is that it doubles for 5 x 7 conveniently.

Any guidance would be appreciated, however, I should have asked before I bought it...