Hi Sunny and Chris --
It may be splitting hairs, but there is a technical distinction between effect algorithms and effect units.
There are separate System effect units called "Reverb" and "Chorus". As I'm sure you both know, different effect algorithms (presets such as "Real Large Hall") can be assigned to a System unit as defined in the "Effect Type List", page 46, of the Data List PDF.
Similarly, an effect algorithm is assigned to an Insertion effect unit. The insertion effect algorithms include many reverb and chorus types. So, one could assign a reverb to the Insertion effect unit for the microphone.
Unfortunately, the really, really good reverb algorithms (REAL REVERB) cannot be assigned to an Insertion effect unit.
Hope this helps -- pj