I checked it out a couple of years ago, on various articles, wiki and reviews and such
- nothing indicates that in theory the frequency content would be different
- reviewers never mentioned anything particular about the saw
But it could in reality in choice of circuit and component be different in how the edge is created.
- suck a level down is discharging a capacitor, and raising it is charging it
- but again never noticed any difference
- digital oscillators are likely more to perfect theory
In Prologue I bought an digital oscillator called One, said to mimic some Moog I believe.
- there the shape change saw from normal to reverse and something else in middle
- the edge is like in a squarewave a series of odd harmonics
- never heard a difference between end points
- Time Shoebridge sell that oscillator, or Sound Mangling
But I used it to counter what analog VCO saw in Prologue do with some interesting result
- a saw mixed to some level with a reverse
- maybe same octave or some octave apart
- so you get cancelling of some frequencies, how much depend of level and which octave
I tried to compare waveforms between synths I had, and found that feeling one was clearly different had to do with SPL, sound pressure level, or volume simply put. Ears are dramaticly different frequency response depending on volume. Sp matching levels perfectly is important if to compare.
I have a NL2X, Prologue and REV2 and have not really dived into comparing closely, but just don't care either. Either synths do what it does. Selecting synths from what kind of saw is nothing I would do.