Just a lil personal insight. I have ordered 3 different research chems over the past 8 months and I got them from 2 different suppliers. All 3 from supplier A were MUCH better than from supplier B. Based on my experimenting with dosing, the potency was the main difference between the products from suppliers A vs B. I got a batch last week from supplier A and the potency seems really good again, like old times.
As far as the products doing what they say, for me it boiled down to suppliers and potency. If you get a good supplier, then you should be getting the real deal that does what it says it does.