Figure id share my test plan and what I'd do if I get selected to test this puppy out.
My wife and I are both iPhone (i have a normal one she has a plus) and Apple watch users(series 1).
Test charge speeds for both plus and standard iPhone. (document charge speeds, note any charge speed differences between plus and standard)
Test overall ease of set up and functionality. (even though it seems pretty straight forward.)
Test things like: does the phone have to be on the pad a specific way in order to charge. Can it be off center?
I have used apple watch stands before and the spot to affix the watch charger in some have a difficult time staying in place and affects charging. So i'd review that for sure also.