Arch Linux is most of the time not more "bleeding edge" than Debian Testing.
But when updates didn't roll into Debian Testing timely this has usually real reasons. Most of the time you don't want those updates on any productive system as there are severe issues. (Except when some more exotic software package doesn't have a proper maintainer team behind; than updates may be delayed even infinitely; but in this cases the quality of the maybe existing AUR packages also often isn't good; exotic stuff is just less supported everywhere.)
But when updates didn't roll into Debian Testing timely this has usually real reasons. Most of the time you don't want those updates on any productive system as there are severe issues. (Except when some more exotic software package doesn't have a proper maintainer team behind; than updates may be delayed even infinitely; but in this cases the quality of the maybe existing AUR packages also often isn't good; exotic stuff is just less supported everywhere.)