For specialized products that require some expertise to be appreciated that could be true (ex high end cameras, guns etc), but for most everyday objects (books, music) anyone can have a valid and often very insightful opinion. Personally for exotic stuff I look up reviews on specialized forums (ex for PC stuff I go to newegg reviews rather then Amazon). Aggregate reviews on those "professional" forums will be an excellent barometer.
On a side note regular people often notice small sometimes obvious things that "professionals" overlook and comment on them.