Consumerlab.com recently conducted a review of Echinacea products. NYBC carries the MMS Pro brand in part because it is a German brand and they have more stringent control over the quality of botanical products there.
Of note, many of the items tested did not specify the amount of Echinacea. MMS Pro did and had higher concentrations than most brands per daily serving.
Read more on MMS Echinacea at the NYBC entry: