And M-11 is a robot with a self-repairing healing factor, force fields and vast superhuman strength. Before you start talking shit for losing to him maybe you should put down your copy of Red Hulk, and read some Agents of Atlas.
Clearly you have no concept of what Wolverine's Berserker Rage is. Wolverine doesn't hate his Berserker Rage and fight it with every waking moment with every fiber of his being because it makes him sloppy and weak, he strives to remain in control because it makes him too good. Berserker Wolverine is the perfect killing machine, created perfect by nature and improved upon by science. He thinks much faster, he moves much faster, he's much stronger, and he is more skilled. He is the best there is at what he does.
Berserker Wolverine is what fighters and strive for when they tireless train for years and years for the right combat responses to become second nature to them, an unconscious reaction floating around in the subconscious, only its not second nature to Wolverine, its first nature. Every fiber of Wolverine's being is screaming at him to fight and kill at every second of every day. Fundamentally is the same as Sabretooth except Logan spends his every waking hour trying to control his instincts, where as Creed just allows them to do their business. Wolverine hasn't traveled the world to learn every martial art disciple to become a better fighter - he never needed too he was a great fighter by design - he's done it to gain some measure of control and self discipline, so he can keep the beast caged. And thats how he fights people the majority of the time, using his immense will power to hold of the beast, while he ignores everyone of his instincts and fights with some measure of restraint. Berserker Wolverine is completely uncaged, fulling giving into the instincts Wolverine ignores normally, and so far as killing is involved his instincts are always right.
The Berserker Rage is weeks of combat compressed into minutes. It is the equivalent of a gymnast preforming a gold medal routine while simultaneously beating two super computers at chess. It is an unstoppable force of nature created only to kill and its the best there is at what it does. The only down side to the Berserker Rage is that he will kill indiscriminately.