Shoes and blisters

I got new shoes almost two weeks ago (on 8/11) a I've worn them for all my runs since then. My previous shoes were Saucony Omni 5s, and the new ones are Saucony Omni 7s, so almost the same shoe. Now I've developed blisters on or near my big toes on both feet. I never had blisters with my old shoes, even when they were new. Does this indicate a poor fit with the shoes or is it just the transition to new shoes? The blisters don't hurt, but it makes me wonder if maybe these aren't the best shoes for me, or maybe I need to get better socks or something. Should I not switch so suddenly to the new shoes, but alternate between the new and old ones for a while until the new ones are broken in?

Any advice is appreciated.

Thanks.