I owned the Intellifex and the Replifex, as well as Alesis Quadraverbs. As stated above, the Intellifex configs are built around a four chorus algorithm. What does that mean, that if you think of a chorus, you have level, feedback, depth and speed. The Intellifex also adds delay and reverb to this chain. So your settings now are level, feedback, speed, depth, delay (length and feedback), reverb (depth, etc). You have four different chorus units on one settings, so you have to go through that string four times. It offers really lush chorus, because you can space it out all over the audio spatial spectrum. For simple delay and reverb, you have to zero out the other chorus strings, to boil it down to the basics.
With the Replifex, they designed it to be analog, with the feel of stomp boxes. So it's much more traditional in approach. Your setup is that you have access to all of the effects, but you can only have 6 or 8 at a time. If you have a midi controller you can turn each effect on/off as if they are stomp boxes. The settings are your standard fare, but the sound of the unit is good. I liked the functionality better, so I sold my Intellifex. I then bought an Alesis Quadraverb and compared the two side by side. I thought the Alesis was maybe a tad more transparent, so I sold the Replifex. The Replifex has some great stuff in it though, the delay spill over was really nice and the tremolo was cool too (actually most of the traditional modulation effects were good (phaser, flanger, tremolo). 99% of the time, I used delay, and I have a MXR phaser and flanger, so I didn't need the bells.