Since laser weapons do not work like those in science fiction games/movies, they need time on their target to burn it. More powerful your laser, less time it needs on target AND higher temperatures it can reach, which means it can be more effective against the same target OR it could be effective against a target it might not have been otherwise. And, higher power means your laser can reach farther out, so it increases your range.
Also, I don't think the increase is linear, so, having 5x more power could result in a far more powerful laser than just 5x. So yeah, that laser is quite bit more powerful and better than ours if it is working as declared.