Seems obvious to me that new Galio is best played as Support
Let's assume everyone reading this has half a brain and already knows why his kit would be good for the Support role and skip to the reasons it's not so good in Top or JG:
-His passive would auto-shove lane leaving him susceptible to ganks when extended similar to why
doesn't make a good top laner(althoguth not quite as difficult to manage), and it's cooldown is only lowered when hitting enemy champions with spells so it would be sub-par for jungle clears.
-His Q isn't the worse for clearing camps but it's not cheap on mana and still pretty meh compared to most top-tier junglers, and is medium length CD.
-W passive only shields magic dmg which only baron deals(from jg). I suppose it reduces the damage of one auto attack form each nearby jg monster per cast, but mehhhh.
-E deals damage but it's a medium length cd and requires mana leaving less in the pool to assist allies or powerfarm.
-R decent spell for a top or jungler but still it's post-6 power stalled in jg and requires having TP up from top lane or galio will likely lose his turret just for using his ult to help an ally outside of lane.
But when you put Him int he support role every part of his kit is 100% efficient.
Maybe I forgot to mention something Or i am missing a counterpoint, please share your thoughts.
In order of efficiency i rate as follows:
-Support:100% -Top:90% -JG:80%