I'm pretty sure the PS Technik doesn't flip the image... that is why it is so expensive. Not sure enough on the stops to give you a solid answer... 1.5 perhaps.
The P+S Technik delivers an upright image, as does the Letus35FE. The rest of the adapters deliver upside-down footage, but those two are upright.
You're looking at a minimum of 2 stops of light lost through either one of these, IIRC. I used the mini35 on a DVX, haven't used it on an HVX, but from what I remember of it, we were doing a comparison between it and the DVX/anamorphic, and we found up to a 4-stop difference between the two (but, attributable in part to how slow my lenses were; some were f/3.5).
We are also doing a short come march with the HVX and Mini35 and are using superspeeds, because of the light loss. I was told the ISO ratting on the HVX with the mini35 is about 140-160. Not too bad but you need the fast lense. Superspeeds go to T1.3.
Ps 35 do not flip.. but be careful on the edges of image it could be a bit dark like shadows... and make sure the mirrow inside is clean you won t notice it on monitor or lcd burt you ll see it later ... Stop is 1 and half .