If the skill has 0 seconds and less damage then you automatically kill the entire system of transformation skills, because these skills become useless.
In any case, now you can play with 2 skill and not just one, well, everyone can decide for himself whether it is useful to him or not, and I will observe and draw conclusions.
I think that , if the skill have an optional buff, would not be useful. Let me show an example: if i have a rk, with this new skill, i deal 100k damage once every 30 sec. That's mean i use triple all time, and every30 sec this new skill. In pvp mean lose lot's of seconds changing skill, pve means occupy 1 more slot on bot system. What i mean is, if this new skill,deal not 100k but 60k, but at the same time it say : when you use this skill create an aura that increase your attack by 3% for a while, or more, when you use the skill you Summon a spirit that stun target or we can have 10000other solution, like this will not be useful . That's my impression but, like you say, we have to see if and how other players will use this new skill