Having the same problem as you guys are experiencing for patch 5.5. Instances where it would freeze at loading screen and would require me to use "command + option + esc" and try to reconnect again. I would get in game but after a while I would freeze again, audio is running but screen would just freeze, I get minimum freezes and crashes of 3-5 per game (depending on longevity of gameplay). I tried to observe it but have not gotten any conclusions to it... it happens randomly, not just in team fight but also when I'm roaming or just in lane.
Not to mention that my ping substantially sky rocketed since patch 5.4 which made me stop playing it as I wait for the new patch hoping it'll get fixed but 5.5 made it worse in my opinion. High ping ranges now from 300 - 900, FPS dropped a lot from 60-90 to 30-45 and the most annoying of all, in-game freezes and crashes.
Whenever I toggle Sona's music it won't show the animations anymore because of the fps drop, really quite weird. I tried setting everything on low but still no success over it.
I tried repairing it thrice now and it still does the same thing. I haven't played that much since patch 5.4 until now or if do so want to be brave about it, I do a custom game first and try things out but unfortunately the same thing still happens.
Basically the things I've noticed since patch 5.4 from playing regularly:
- High Ping
- FPS Drop
- In-Game Crashes / Freezes
*Also using Macbook Pro (OS X Yosemite 10.10.2)