The weight of A is higher as compared that of its counterparts.
The weight of A is high as compared to that of its counterparts.
Which word is more suitable —'high' or 'higher'?
I don't like Joe's answer for two reasons. First, "The weight of A is high, compared to its counterparts." begs what the absolute magnitude should be for this to be used, i.e., at what point is the weight of something "high". Second, high usually describes height; and heavy describes weight. It doesn't make sense to say "it weighs higher" or anything like that because we are talking about weight not height. Something is heavier or weighs more.
The best, in my opinion, would be:
A weighs more than its counterparts.
A is heavier than its counterparts.
I prefer the first slightly more because I (as a reader) have to do a lookup in my brain for the phrase "is heavier" which will return "weighs more than".