Reviewing the work of others requires tact, diplomacy, judgement and thought. These attributes are even more pertinent at GA/R because, in contrast to GAC, the principal editors of the article are usually unwilling participants. The goal of the review is to improve the article, but reviewers should make genuine attempts to elicit the willing participation of principle editors in the process. You may gain a better GA by being authoritarian and offhand but you risk losing the author of, potentially, more GAs in the future.