The Demeter is good, but does a very specific trem style and has an annoying volume
boost. Not a bad pedal but not as good as I was expecting.
The Semaphore, on specs, is perfect. I thought it would be - and wanted it to be - THE tremolo.
The problem I had is that it altered my tone in a way I didn't like (thinner, with an almost harsh, treble-y edge) which made it unusable (for me) with any kind of distortion. It sounded quite nice clean.
It also annoyed me that the speeds I used most were around the top end in the slow toggle settings, and in the bottom of the high speed position - so I was continually having to switch between slow and fast.
(For the record, this was a 9v Semaphore - bought new - from 1997; the newer models may have changed.)
Have you ever tried the EH Stereo Pulsar? This is what I use. The Semaphore that I've tried in the store is a tad better, just not sure if it's $100+ better?