Definitely. Aegislash is no doubt the best Pokemon that came out of Gen 6 besides the the mascots and the Megas.
All you have to do is look at its stats and access to King's Shield to see this. With King's Shield, it can cripple physical attackers, forcing them to switch giving Aegislash an opportunity to set up Swords Dance and then deal heavy damage with its base 150 Attack in Blade form. It can also use Iron Head which is really excellent for Fairies, making Aegislash a good partner for Dragons. One of its few flaws, its disgusting Speed, is covered by Shadow Sneak which has priority. Blade Aegislash has a high attack stat that makes up for Shadow Sneak's base power.
It can run defensive sets as well thanks to how versatile it is. Shield form has 150 in both its Defences, which is pretty much off the charts, even for OU.
I don't need to say anymore. Essentially having base 150 in all your stats but HP and Speed is absolutely amazing.
