I like the new Galio but...
So just taking the new Galio based on his current state and not comparing old to new. I really like the new Galio and after about 30 ranked games I have about a %50 win rate with him mostly top with some mid mixed in in.
He is fun but being a tank in Bronze he is not impactful enough IMO on his own to really force your will and directly contribute to carrying a win. I have been building 1 AP item and the rest tank based on enemy team comp.
His wave clear is good after you get some mana and he can roam fairly well with his Ult which is fun if not slow and telegraphed. The issue I have is the fact that you need your team to support you and take advantage of your plays. You can't really split push or take solo objectives. AA are deathly slow and you only really have 2 attack skills on fairly long cool downs and your AOE magic AA ever 8 or 4 seconds if you hit a champ so killing even squishy targets mid/late game is a challenge.
So far looking at his stats over the last 7 days he doesn't have a positive win rate until you get to Challenger with only 52 games played. Every other division he is around 46/47%.
Overall fun, decent trading pre L6, good wave clear, Ult is a double edged sword good to help others useless in lane to help yourself. Team reliant like most tanks. Fairly limited DPS. Suffers the same as most tanks in the current meta. Anything you can do a bruiser built champ can do better.
Also no matter what tank I play Maokai, Rammus etc bruisers/juggers take far more damage per game than tanks.