Absolutely Jon. Plus agents are people and they all place emphasis on different things. I've heard some agents in the past who said that they didn't put much emphasis on the synopsis or don't read them, whereas it's a more important tool for others.
My logic when I submitted is that I wanted to put all chances possible on my side to stand out in the sea of submissions. I had heard a few agents saying they like comp titles, some of them who were on my list so I decided to have comp titles on my letter. Never heard anybody who said they hated so it couldn't hurt, just help. But that's just me.