I only have immediate access to the Carl Fischer editions. So I can't speak as to if they're much different, but the engraving is clean and easy to read. At least the No.2 studies are the same as in the back of the Ambrosio edition by Carl Fischer.
My guess is that most of the editions use the same original plates (i.e. neither have been re type-set), so they'll be essentially identical.
Note that Carl Fischer publishes two versions of the Method. One edited by Bettoney ("enlarged edition" with a white cover) has the Midle "scale studies" while the other by Ambrosio (purple or red cover) has the Op. 8 No. 2.
M.M.A., D.M.A. University of Illinois at Urbana/Champaign: B.Mus. Lawrence University
Bassoon professor at University of Wisconsin Eau-Claire
Maker of the Little-Jake electric bassoon pickup and Weasel bassoon reeds