Just read the Harmony Central review, strange how opinions differ..
I honestly think it is a good unit, like all unfamiliar gear you need to get to know what it does, it ain't 'plug & play'.
I use it with my new Ashdown 300 EVO combo and I did have to adjust some of the controls differently to what they are set with my Roland Cube 100.
I bought mine blind, I didn't even try it out, I don't think BOSS would make a crap unit, sometimes it is a case of a bad workman blaming his tools.
My review in dave's link is my opinion and I am happy with what it does..Best of luck