Starting where we did at the Montreal River access, we were really glad we did the loop counter clockwise. The portages leading to Solace Provincial Park were generally pretty easy going, and when we got to Solace where they become more rugged, we were into a groove of portaging daily, both physically and mentally. By the time we arrived at the long 3 km portage out of Gamble Lake we felt pretty good, and our packs were way lighter as we almost depleted our food supply by that point.
If we went counterclockwise from our access point I almost feel like it could've set a different tone for the trip. (or at least for the first few days). Starting a trip with full heavy packs at a 1,050 m portage with a steep incline would have been brutal!
I have read of others starting from the Sturgeon River as well. I think we just wanted our first full day of the trip to be portage free with just lazy paddling (and a beach..lol), so starting at the Montreal River with Smoothwater as our first night felt like a good choice for us.