I have just run comparative CPU usage tests on the various reverb opcodes in 
a stereo setting. The opcodes tested were: reverbsc, freeverb, reverb (2 
units required) and nreverb (2 units as well).

The test orchestra consisted of a simple (vco2) oscillator, stereo locsig, 
locsend and denorm. Tests with a single voice had the reverb within the 
instrument. Tests were also run with 16 identical instruments running 
simultaneously, but with a global reverb accumulator into a separate reverb 
instrument.

In WinXP (and additional applications minimized), average single voice CPU 
usage (percentage):
reverbsc: 7
freeverb: 6
reverb (2 units): 4.5
nreverb (2 units): 5.5

with 16 voices:
reverbsc: 11
freeverb: 11
reverb (2): 10
nreverb (2): 11

My conclusion: The particular reverb opcode chosen makes little to no 
difference in any but the simplest settings. Use the best quality available 
(which IMO is reverbsc).

So, I'll be using reverbsc even for OPLC. (I like reverbsc's ability to 
randomize reflection time; this makes the reverb sonority less 
smooth/regular, which helps with sustained tones.)

Would anyone make a different choice?

Art Hunkins