The moment that you do group tests, it becomes comparative, and one ends up a winner, another the loser, and the others in between. U.S. mags would never contemplate this as they'd immediately lose all kinds of advertising revenue, plus many manufacturers would stop sending them freebie examples (long-term loaners) to review.
Of course, given the access of the most of the population in the U.S. to easy audition of multiple competitive components--which is close to zero if you don't live in NY, Chicago or LA--then precisely this kind of review would be the most helpful and a genuine service that a magazine could provide.
Of course, given the access of the most of the population in the U.S. to easy audition of multiple competitive components--which is close to zero if you don't live in NY, Chicago or LA--then precisely this kind of review would be the most helpful and a genuine service that a magazine could provide.