regrettable
adj
that is or should be regretted 令人痛惜的; 令人遗憾的; 可悲的; 不幸的
regrettable failures, losses, mistakes, etc 令人惋惜的失败、 损失、 错误等
Her rudeness was most/highly regrettable. 她粗俗无礼, 令人遗憾.
I suggest that we ask users of this machine what they think about it. We can photograph them using it too. Then we can put their comments at the top of the advertisement in big print. We can bring in some humour too. People enjoy reading humorous ads.