Ultimately the looper has to suit your needs as some people want to play to a click, some want backing tracks, others want layer flexibility.
I’ve owned dozens of loopers and the two that have stuck with me up to today are the Boomerang III and the Aeros Loop Studio, but I use both the same way.
I record a short freestyle loop to “set the tempo” instead of a click or preset tempo. Once that loop is closed, either looper allows multiple tracks and overdubs to be created in increments of that first loop. Sometimes it ends up being a scratch and a thump on my guitar as a “click-TACK” and then the next track might be 8-12 times that rhythm.
By the end of the song, everything is erased. It works for me because of the flexibility.