I do not have one; I use my knowledge of the gear market to tell people what can be done (a recent example).

Only just seen this thread. I use a boss rc300. Loads of input options. Loads of output options, including routing stuff to the dedicated "sub out" jack socket. Three loop channels, individual track lengths. Sync or unsynced. Expandable with switch inputs. (Limited) onboard effects.. A tiny bit of global reverb is good, it smooths over the transitions/loop repeats. Loads of midi options. Sync it up with an external drum machine or even another rc300.

In fact I've just posted a video on the showcase using it.

You can build up loops REALLY quickly, but you can also deconstruct them with the "undo" feature. Also the two extra switches (all start/stop and fx) and the rocker pedal are assignable to any one of a load of parameters.

Highly recommended.

Rob I see you are a magician of tech. There is only one quirk which I wonder if you can explain about the boss rc-50 (which I use). The loop timing is perfect if you find this one setting, but if you make a long loop you have to play the first downbeat of the loop or there is a lil ga/stutter. Now this is easily overcome by knowing to play till the end of loop and like one second more but whats up with that. And like some loopers are just not "dead on" even with swift footwork.

I have used many loopers (echoplex, jammen, boss rc's, dl4,...) and have settled on the boomerang. I use 2 rangs + sidecar. All my instruments run into a 1st mixer (guitar, bass, stick, organ, synth & keys), loopers receive a stereo submix of this,then dry signals + looped signals go to 2nd mixer. Loopers run 100% wet to preserve dry signal. 2nd mixer (total mix) goes to monitors and recorder. I use a BeatBuddy to provide master midi sync. In this mode everything works perfect. Loopers start/stop with BB. 2 rangs provide 8 stereo loops. The boomerang has 0 issues with exact punch-in, perfect midi sync, great sound quality and lots of performance options. Easily beats all the other loopers I've tried. The echoplex (I have 4) were the closest in performance, but a hassle to connect and 4 rack spaces + foot controller and do not midi sync well. The boss units do not sync well with midi either, but were pretty nice otherwise. Jammen were OK, but boss was better and rangs much better. The only downside I see for the rangs is the lack of ability to save loops; it is definitely a performance oriented device. I have found a way to use the midi sync to slave my tascam dp-32 to all this and can record the drums + 8 loops realtime (as a stereo mix) and then use the dp-32 as the midi master, erase the loops on the rangs and start over with the dp-32 recorded loops as the click track/midi master. The only problem so far is that the BeatBuddy does not stay in sync as a midi slave (although that is supposed to be fixed in an upcoming firmware update) so the drums have to be recorded with the 1st looped tracks. It will be better once the BB can slave properly to the dp-32. The rang is more expensive than the others, but worth it for my needs.