And a PC tip, just to even the scales a bit...
I'm using Sonar 6 PE as a host. If I insert Replicant as an effect insert into an audio track (containing a drum loop) I don't hear any effect at all. Am I missing something obvious ?
Now, for what it's worth, I sort of knew the answer, and have for a long time. Way back in the old days, when real men edited audio by splicing magnetic tape, Sonar was a DirectX host and DirectX was a viable platform for plugins. Cakewalk provided a wrapper with the host (but not of it, natch) that would wrap all your VSTs as DirectX plugs so you could use them in Sonar. A nice side-effect would be that you could use them in all your other DirectX hosts like CD Architect and Sound Forge and Acid (I sense a theme here.) In order for a VST to receive host tempo information (which Replicant needs because it's, like, a tempo effect), you'd have to import it as a DirectX Instrument.
Why Cakewalk didn't just automatically say "all VST effects might or might not need tempo information, sort of like Schrodinger's cat might or might not be dead, and we don't know, so let's not add a layer of complexity for the user, and just go ahead and assume they're all gonna need it" is utterly beyond me. (I'm going to need a life preserver to save me from that metaphor.) But they didn't, so that's what you had to do.
But that was back in the bad old days, when you had to use 8" floppies and MIDI hadn't been invented yet. Nowadays, Sonar (and its offspring Project 5) are true VST hosts so this isn't a... oh, wait...
Actually, you _still_ have to let the VST->DirectX wrapper that Cakewalk uses for all its host products know that a plugin might need tempo information. I find this disconcerting when pretty much every plugin released has some sort of tempo-based gee-gaw. But since the "import as a DXi" thing didn't make any sense at all, they renamed that checkbox, then added another one, just in case you weren't confused enough. Here, provided by the above customer after we figured out what the hell it was really called, is a screenshot of the appropriate checkbox:
Anyways, people that use Cakewalk hosts: you're welcome to keep writing me, and I'll be happy (as always) to keep answering the same way, but in the event you do a Google search _before_ you write me, there are enough keywords in this blog post to virtually ensure that it will come up as the first hit for the search "Replicant doesn't do anything in Sonar" so here's your answer. Configure that little bitch as a tempo-based effect, and you'll be good to go.
(Thanks to Mike Callon for the second screenshot, and I should point out I blatantly stole the first one from this article on the SOS site. Parenthetically speaking, anyways.)