If I had to say anything, its that they went a bit overboard with the HP/5 thing.
Sure, 2 hp per second at level 1 is a little.. outrageous, but still To bring it down that far?
I'd say stop at the middle ground of 7.5 hp/5 (+0.7 per level)
You could argue that mundo has a lower natural HP/5 then her even now, and I'd agree, but with Mundo's passive. He can go where he pleases the second he gets that Warmogs.
To be fair. The ult nerf was kind of needed. It was up a little too often, but then again, the same thing could be said about blitz and the 30 second cooldown. It does not give him a 20% steroid, but it still does a fair amount of damage and can mess up your entire plan.
I got too off topic.