I'm using a Boss GT-100, with an ElectroHarmonix Freeze pedal in the effects loop.
For bass I am mainly using the 100 for the effects loop so that I can help create a pad with the Freeze pedal, but still have my original tone when not using the Freeze. It really fills out when we don't have someone on keys.
It doesn't hurt to be able to add a little grit from the GT-100 to the sound when needed.
The Freeze pedal is amazing; polyphonic; I use it for a lot of root-5-octave sounds for beefing up the pad the keyboard is playing.
It does color the tone, however, so I have the effects loop programmed as a parallel loop, so that I can have an uncolored signal in addition to the Freeze signal.
The Freeze tracks very well, even down to the open E. It doesn't like the low B on my MTD, though.
I'm using a RNC compressor after the GT-100 right now and it does a nice job.
That feeds a direct box into the FOH snake.
I occasionally lead worship with an acoustic guitar, and for that I love using the multieffects unit; it is hard to lead in prayer while bending down to change the effects for the next song on a pedalboard. ;~)