Although not considered the best option for
SSB, that comparison shows a class C will indeed work on
SSB. I was actually under the impression that a class C on
SSB would be a whole lot worse, in fact I was under the impression it wouldn't work at all. If I only had, or could afford, a class C amplifier; I would not be concerned about using it occasionally on
SSB.
And to be quite honest, only someone with a base that could fine tune that signal in, for an hour long conversation, would ever really know (or really care)...most of our DX contacts are for under a minute, then we move onto the next one. I wouldn't be able to tell if that was a class C or not...I would have assumed it to be a poorly tuned radio or the conditions at that time, which brings me to my next point.
Garbage in is garbage out...I would like to know how that Longstreet was modified, if at all. A clipped radio, overmodulating, would likely cause more issues and heartburn at the receiving end than that Class C amp.
For the record, I run two
SSB setups; the radios are tuned by a competent technician into AB-1 amplifiers. So I really don't have a dog in this fight.