I'm not sure about the superfield, but I recently purchased the digital widefield and digital clearfield (BIO) lenses and have some opinions on each.
The digital widefield is a very good lens overall. The view compared to the 90D is smaller image detail, but a more comprehensive view. With a fully dilated pupil (no magic lens, a fully dilated pupil is the key) and eye movement I have seen ora in the slit lamp. Also, once I learned how to use it, reflections are less of a problem with the DWF lens and the view through undilated pupils is excellent. Having said that, it is a difficult lens to learn the skill of using a HP lens. I remember starting out learning HP and tried a DWF and just could not "get it". It is a larger diameter lens and you have to hold it closer than the 90D to the eye to get a good image, but I had alot of other problems with my technique to worry about then. So I bought a 90D and lived with it through school and clinical rotations. I recently had the chance to purchase one and practice with it again and now use it over the 90D exclusively. While the image is great I do find that I am missing some retinal detail, so much so that I will use a 60D/78D lens with a diabetic patient or other pathology.
I gave myself a month to use the digital clearview lens but feel that the 20D was sufficient and I am not getting as much return on investment as with the DWF. Same concept as the DWF lens applies, wider, more compressed view, which honestly is compressed enough in the 20D. Some doctors are using a 30D lens to view to midperiphery through undilated pupils in children, which I have tried but have not had much experience with. That is the only reason I think you would go wider field and smaller image in a BIO lens, and the 30D does that better. I will probably go back to the 20D at the end of this month.
Long winded, but hope this helps.
