Well. He might be right for blades which you consider using on the long term. But I can pretty quick judge if a blade is worth playing for 3 month or not. And with experience in trying new stuff, you also get a good feeling on the differences early on.
My routine for new material usually includes playing material for like 10-20 hours (3-5 training sessions). This eliminates the usual day-to-day variation in your own form. If the material is working as expected, I continue using it in training and matches. Especially matches is import, here I agree with ZJK.
If that works out ok, there is still the question, does it over more than my current setup? If yes, keep it, if not leave it and turn back to old setup.