The jungle seems to be the nesting place for imbalance in Season 5.
Pre-season 4.20: Huge changes, made WW OP as well as a few others.
5.5: Introduction of Cinderhulk leads to Gragas and Sej being OP.
5.13: Runeglaive junglers and Devourer got buffs. All hell breaks loose. There are multiple junglers with 60+% ban rates. The top 5 banned champions are all junglers. The pros are only using Runeglaive, and Solo Queue is only using Devourer.
And in 5.16, this will not change a whole lot. Three full patches after the big, meta-changing patch, we have seen 0 jungle changes other than a jungle clear speed buff for Runeglaive.
I wouldn't mind seeing some jungle balance at some point. I miss jungle balance.