If you use VSTi's (a question you still didn't answered) then you can use the volume per note as described above.
VSTi's are instruments VST, yes? i don?t use it.
i only use (for now) samples. i?m using a "reverb" VST effect.
So, you want to change the amount of reverb on several channels right?
In such cases, its much easier to just use several instances for different instruments (not necessarilly channels) Remember, you can assign a plugin to a channel, but also to an instrument in the instrument tab. (not both though, atleast it can be, but the instrument one will have priority over the channel one).
If you do more reverb plugins over different channels, and configure each, you don't even need to alter them in your song.
If your computer is not really slow (eg. 1000mhz or slower) but using the reverb makes it slower, then it can very well be that your reverb plugin is a bad one, eg. consuming unnecessary much power)
