Yes, technically it is. However, it has always been comparable to OHA Jr.C. One of them is "mislabelled." In my opinion, its the OHA one that is, but that's the one with more teams, so I'm not sure they'd agree.
Ok, so Barrie. Well, close by Alliston is one of the top 3-5 teams in Jr.C year-in, year-out. They always seem to have a competitive team. This year it looks like Stayner is going to give them a run for their money. Midland, Schomberg, and Orillia all also have teams in that league. To the best of my knowledge I can't think of any "horror stories" of any teams in the GBMO league (re-labelled the CARRUTHERS division this year, as part of the OHA Jr.C amalgamation).
If you wanted to venture a little further from Barrie and see another league just for comparison sake, then Georgina (Sutton/Keswick) has a team in the old Central loop (relabelled as the ORR division), and they haven't had too much on-ice success the past few years. So they could possibly represent a baseline for you.
Again though, I caution, scouting from the stands is only one aspect. Coaches recognize hard work and team-first attitudes.