Based on my reading, the Solida is a decent folder. The examples I see on eBay have the Radionar lens, which is a well made triplet -- when stopped down past f/8 it'll produce results almost indistinguishable from a Tessar. There's little to go wrong, with no frame counter (red window only) and no RF (so no linkage, no half-silver to go bad, etc.). It's scale focus, but with a little practice you can learn to hit the focus within a couple inches at distances where it matters.