If you qualify for both of them right now, you should take CEC because it is faster because you skip the extra stage of PNP nomination. If you can apply through PNP now but must wait before you qualify for CEC, then it is a question. You can contact your PNP to see how long they take to nominate and you can check trackitt.com for other peoples timelines to see which is faster.
One downside with PNP employer stream is that if you lose the job, you may lose your application.