I was curious too, so I did a quick model of a 152 F8 triplet using FPL-53, changing the matching glass to Ohara's version of Schott BK-7, and reducing the airgaps to something more normal (0.2mm), and letting R5 vary from the other internal radii. It's actually quite good, even allowing for it having best correction in red. At best focus in red, it has a strehl of .995, blue .856, and green .958. And since it's slower and smaller than the 180, I don't think an asphere would be needed. I'll attach the Oslo file. This was a bit hurried, I'm doing this on a quick work break..later I'll see how it does in violet light and compute the (theoretical) polychromatic strehl, my hunch though is it will be close to .95.
I think this is quite an important post. It may be that the SV180 is an outlier (for whatever reason.. still to be determined, but possibly design scaling?) and the other SV scopes may well meet acceptable 'Specification'.
I don't have a cake in this bunfight, I don't own an SV, but I do think that SV deserve a fair hearing, rather than this somewhat vindictive dogpile that seems to be firmly rooted in past histories with several contributors.
We are, after all, talking about the potential failure of a US Company here as a result of the negative image now associated with ALL SV telescopes as a result of the test of the SV180, and ongoing mud slinging. You may have your own reasons for disliking SV's approach to marketing but I'm sure you wouldn't want to celebrate the loss of a home grown manufacturer ( and spare me the 'we are only helping SV improve their quality' arguments, gents. Crocodile tears don't wash hands clean)