All the bad and good you could say about a leslie is there.
In the end, owning one and using it for keyboards or synths is just plain amazing.
Something magical about a good player and the sound of the start up and slow down of a real rotating speaker.
plenty of emulations out there far as software, for recording projects its perfect.
Having a Real leslie in the room with you and watching that thing spin, is different story.
leslie sold parts to other manufactures, i never owned a real leslie. I had a 1x12 Wurlitzer extension cabinet that used same rotor, bearings, and amplifier as a leslie. was essentially leslie parts. leslie had a 1x12 model i forget the number. guitar players really love them
anyhoo was fun with bass. more fun with my rhodes electric piano. eventually i changed the speaker out for a eminence speaker so it then handled a good 100 watts and worked good with guitar amps as a amplifier. i powered it with my fender twin for 100 watts or blues deluxe for 40 watts. sounded amazing with guitar.
Univibe is 2 stage phaser, one stage is in outer space so you really only hear one notch being modulated. so its a dam good rotary effect.
other boss or dod or millions of other phaser usually 4 stage or 6 stage phasor. usually have more feedback and other krap that makes for the really annoying swoosing stupid phase sounds.
As mentioned Electro Harmonics, Small stone is probably one of the best 2 stage phasers for Bass, also the more simple MXR phase 90 is much more simple 2 stage phaser that is not so swoosh and dumb sounding
if you remember the 20 buck wonder pedals before berhringer was the plastic danelectro little plastic pedals. i think the chicken salad was a uni vibe copy. using light sensors and everything. cleanded up a little with few opamp buffers. sounds same just less noisy than real univibe