Now that I own an S3 too (got lucky, 20 Euros at a flea market for a fully functional unit, only a bit dirty), I can only agree to the enormous similarity with the Revue 400 SE.
Both cameras are the same size, even the lens barrels seem to be identical at first sight, yes even the front lenses have the same diameter. Hmmm. All functions are identical, both cameras have self-timers, hot shoes and X contacts, shutter speeds from 1/8 to 1/500 and B, to set B you have to press a small ridge on both cameras. They both have an exposure lock function.
The differences: the S3 has an almost brilliant flash system with daylight compensation, and knows somewhat different materials and finish. (The Revue makes the more solid impression, at the same time the S3 is *much* better built and more solid than the C35. In the Revue both the tops are brass, in the S3 they're aluminum. The rest of the body seems interchangeable.) In the Revue the aperture blades are in front of the shutter, in the Konica it's reverse. Maybe there are more differences internally, maybe not. I haven't peeked inside the Konica.
You could discuss whether the lenses are built or just named differently. 38 and 40 mm aren't very different when you consider that Leica 50mm focals have a 53mm focal length … I haven't disassembled the lenses nor really tested them, so I don't know anything at all. Both lenses are in any case top of the bill.
You can say this much: if you value prestige and a camera listed by Stephen Gandy, or if you flash a lot, take the Konica. When you're after pure quality for cheap, take the Revue. But on the other hand, I never take flash pictures and nevertheless prefer the Konica.
The Revue's viewfinder and rangefinder are good. The Konica's viewfinder and rangefinder are better. Much better. In direct comparison to the Olypmpus SP I'd have a hard time giving give the SP the edge over the Konica, which means a whole lot. Composition and focusing are fun with this camera, even in low light. The viewfinder is large, bright and free from distortion, the rangefinder area is similarly large, bright and contrasty.
This camera was only available, as far as I'm aware, in "professional" black only (anodized aluminum, not painted brass).
The flash automatics: when mounting a flash on the hot shoe the flash program is automatically activated and the aperture controlled not by the light meter, but parametrized by the guide number, set by the chosen distance.
The special thing: the automatically set aperture (given by the distance and the guide number) is shown with a green bar in the viewfinder. When you then set the shutter speed so that the light meter needle is inside the green area, you have both a correct flash and a correct daylight exposure. Sounds complex, but it is actually very easy and extremely practical. In any case unique!
This camera too lacks a fully manual mode. You can nevertheless check time (directly) and aperture (through the information in the viewfinder), so in the end you're still in control. When the battery empties, you can still take pictures, but only at f/1.8.
The PX 675 mercury batteries no longer available due to environmental concerns can be replaced by 1.4V hearing aid batteries of the same size.
This one was in remarkably good condition despite its doubious flea marked pedigree and the remarkably low purchase price. However, I had to replace the light seals, adjust the rangefinder horizontally (adjustment screw ist reached without furter disassembly behind a cover screw in the top film guide rail - easy) and on one occasion the coupling of the speed and ASA ring to the light meter cover diconnected (The light meter is covered partially by a ring with little holes in it the size of which varies according to the set film and shutter speed). For this operation, simply unscrew the ring around the name plate ring around the front lens, then cautiously remove the name plate ring itself which contains the meter cell and thus is cabled. You will find the coupling instantly. Arrange it and refit, making sure to fasten the outer ring with the necessary (but not with brutal) force.