Yeah I am using it from a couple of days.
However one thing just does not make any sense to me. If they could make the buffs last longer, why on earth make it more than 1 minute?
It just does not make any sense, if a buff originally lasts for 45 seconds making it last 60 seconds is literally almost no difference, I still have to buff each minute or so.
It blows my mind why they didn't make it longer, or at least make I scale like 10 seconds extra each level.