Baron buff is just way too strong
It's almost impossable to clear the minions. They just get way too much health. If someone gets baron you can guarantee that at least 2-3 towers and an inhib is going down. With old baron buff you could at least hold out under tower and stall till it was gone while they try to siege. This buff, you can't hold off a siege period. Yes, they just nerfed its duration but the issue is that the minions are op. You can have the best waveclear team and not be able to clear them before your tower goes down with the amount of health they have and the fact that they get so big that they are more spread out and you can't hit as many minions with aoe. It's impossible to hold out for 3min. Baron is almost a guaranteed insta-win no matter how far behind you are.
EDIT: not to mention the stats it gives you. One or the other need to be toned down. I think the minions are enough of a buff that you don't need the personal stats as well or else the minions need to be toned down extremely.