Here is a picture of my ETX-90 OTA atop a home-brewed DS-powered fork mount.  Two features of this
mount:  the fork is tall enough to mount a DSLR camera at prime focus and the electronics is all contained
within the fork so that there are no wires to twist -- the right ascension drive motor turns about a fixed shaft.
Results are more than acceptable.  I get pointing accuracy comparable to the ETX-90, vibration is well-damped
and tracking is excellent.  I probably didn't save any money going this route, but since I'd bought the telescope in
 its spotting scope configuration it was either buy a whole ETX and try to peddle the used OTA or buy a motor
set and con a machinist into fabricating the pieces in his spare time.  The latter was more fun, even if it did take
about a year to make it happen.