I am currently using a Pigtronix Infinity. It has a few features which to me are great and set it apart. At the same time there's a couple things not to like. - $499 list (!) glad I got mine for 299 used. - locks up at least once a day requiring me to yank the AC adapter. Apparently this is a "feature" as their support told me not to leave it powered on for too long. Here's what I really like about it. - Allows me to use the two loops either as two completely separate layers to play back at the same time, or to make a two-part tune to practice over. - Individual loop volume knobs - Holds 50 pairs of loops - Built in application (it's stored with the firmware, so you just launch it after you connect USB) Things I don't like about this looper: - aforementioned lockup - has a setting for # of loop storage slots vs. max loop length. Every now and then I record something that exceeds the loop length and it just stops recording and plays back immediately at that point. - When you unplug USB after transferring loops to the DAW, you have to power cycle it to return to normal operation Things I haven't tried yet: - using loop aging - using varispeed Things about this and other loopers that I don't care about one way or the other. - Dual/half speed and octave silliness - Reverse - MIDI sync - I thought I would care, but I've just gotten better at making loops correctly the first time - rhythm tracks - I'm generally capturing ideas from the guitar. I can use the DAW if I want to sync to a canned rhythm track - doing a lot of overdubs on a single loop. I do it sometimes, but if it turns out to be something I like and want to work on in the DAW, I tend to redo it all. - Stereo - although I did use that to good effect once with a synth pedal on one side Pigtronix now makes a trimmed down version which only seems to support the two-part mode (not the individual layering mode) and only holds one pair of loops at a time. I had a couple Digitech Jammans, got rid of both of them, and they would let you select a different loop which would start when the current one was done playing. Main thing I didn't like about those was the Windows app to transfer loops to the PC was beyond confusing.