I could have been biased as I hated the remote control function (you needed an add-on laser sight on your remote and special forces training to hit the exact and precise right spot to make the knob turn!).
So that is how to use the pre90 remote, I also had major issues using it. However, the biggest problem with the pre90 (forget what Stereophile says) is that it has volume issues with almost all amps. It worked great with the Benchmark AHB2 and the Parasound A21+. With about 4 other amps it was crap.
When I say the Benchmark LA4 was unlistenable I am only referring to the RAAL SR1a (a great piece). Just bad synergy there. With 2-channel gear the LA4 always worked, unlike the pre90.