Alot of people says its counter productive but in a pack if 9+ monster it is not. Take Sohm Al HM, after the 1st boss you get 5 fishtoad guy following with one of them + 2 shell monsters. I don't remember how munch MPs I get back everytime I get hit but its over 320. Now if 6 of these 8 mobs hit me its 1920 MPs gained while the 2 attack that where dodged helped the healer. Meanwhile Abyssal Drain hit each monster for 800 to 1.3k and heal you for the same amount, helping the healer further. I may be wrong but it has always worked well for me, places like arboretum felt like a breeze because of it.