O-roll and G-roll instruments are very different and musically
different.  One would have to listen to both instruments for a period
of time to decide which is best for that individual.  "G" rolls are
coming from Ed Gaida.  "O" rolls are more difficult to obtain at this
time, but in this business things change.  Ed Gaida's web site is
http://www.edgaida.com/

One of the drawbacks on the built-up machines has been the quality
compared to an original machine.  Many of the build-ups are not as
musical as the original machines, in my opinion.

Don Teach - Shreveport Music Co.
Shreveport, LA