I think SSM lacks the star-power after O'Rourke. They are returning most of their team and they will be as deep as anyone up front with Trott, Kerins, Kartye, MacKay, Dickinson, Pytlik & Carroll among others. But none of those names jump off the page like Phil Tomasino, per se. Goaltending is also a question mark as you mentioned. They also don't have a ton of draft capital, so a big addition likely comes at the cost of Bryce McConnell-Barker. Oshawa IMO still needs a big name D man but they have the draft capital to add that kind of player.
I think both teams are in good position, but I give the advantage to Oshawa. I don't know how much of a factor that is when it comes down to it. Should also be taken into account that if there's realignment, SSM is going to see a whole lot of North Bay and the Quinton Byfield-less Sudbury Wolves.
Like I said, any other year I want it in Oshawa a million times over the Soo, but it's a weird year and maybe an opportunity to try something new.