I personally think that if you find a job and receive a job offer, you will get PR easily in ANY province. If you don't get a job, and you are thinking of it ahead - why would even go to Canada?
Regarding the Express Entry - nothing has changed actually, even improved. You still need a job to get PR. It was with CEC and it will be with Express Entry, everything remained almost the same. So why would even argue about that?? Just read the explanations CAREFULLY on the official websites - and everything becomes more clear.
And of course it all depends on the job you do - if you are coming to canada to do a "dirty" job,or if you are currently doing one, it will be way toooo difficult for you to get PR in ANY province in Canada.
So all in all Ontario is not harder, and not easier to get PR. It all depends on you, but not the rules.