In fact, with this pack of two 9V batteries "PlusPower" there is nothing wrong in qualitative terms. If these batteries are probably hardly less powerful than the range "UltraPower" also available in 9V (and other formats for that matter), they remain as Duracell 40% more powerful than the classic range. They also benefit from technology "Duralock" that keeps the battery at its maximum energy level, even though it is not used immediately.
In short, everything is there to reassure consumers. The price, lower than that of "UltraPower", will perhaps move towards "PlusPower" because the apparatus using 9V batteries are generally little greedy (and in contrast to AA or AAA batteries, it will probably better to move towards the range "Ultra"). After that it is up to each judge the relevance of taking the batteries offering the best guarantees of duration of use according to his needs!