Regarding those enemies it normally takes one row per turn for me so it would be a 2 turn extension on those "thrash" mobs but then again you could drop that clock that cuts 5 turns of cooldown on your main and assist Eidolon, disregarding that on my weakest teams burstless I kill Ultimate advents in 3 to 5 turns so it's definitely not for me in the long run but I see the versatility in a team that needs it (say Thunder that struggles a lot at the moment) It also comes by depending on the player's playstyle.
I find those effects like God Kaiser Dragons or buffs as Lilims to be pretty much irrelevant but at the moment I will get Jack and all the Eidolons that come my way with over 40% Attack Increases and over 1850 Attack at Level 100 for obvious reasons (plus the 10% attribute increase on monochrome teams), this months to come will be really good regarding Eidolon Strength