No, I still think it is a fair consideration to make. When people use Powerfull in stacks, it is almost always used in a non-synergistic manner. To bring out additional recovery benefits, the only stackable supplement that comes to mind (synergistically speaking) would be a ZMA formula (ZMK's good to go).
I think one bottle would give you a good idea about how you respond to it. Increased recovery is apparant well before a month's time, and if you pay close attention, you'll be able to draw a pretty fair conclusion after a month.
The most noticable difference I find is the more recooperative sleep when dosed before bed, which starts immediately.