I'm not the most objective as I have not the expereince with other loopers. I do feel the RC-50
gets a bad rap in reviews due to it's complexity, and over-hyped by it's own liturature.
I like the way the midi out works for me. The place I got mine has another and I would like to see
if the RC-50 would sync to it's own kind. I have heard the problem is in using the midi in. I haven't
had a need as my DR-5 syncs to the RC-50 just fine. If I do use 2 units I would set them up in single-mode and use the second unit to bring in multi-mode.
It can be set up with a feedback loop from the subs back to the aux input to give decay while recording.
It is also possible to have swell and decay when loops are being stopped/started. These 2 things are very useful.
As Buzap indicates, it does NOT handle tempo changes well at all. While easy to set orginal tempo and send sync, it will not give a good sound when tempo is changed.(warbled)
There are a LOT of menus for set up on the unit, some global and some patch/phrase specific, which is nice. The drawback I see might be the price depending what you are looking for. I think you should try someones out that is familar with it, before making a purchase.
I like using a mixer with the unit.
Capt.