I don't really remember the Competition, looks like it was a down-scale Pro? Anyway, I did my first season of randonneuring on my '80s racing bike. It was okay. There were things about it that were sub-optimal, like the lack of fender mounting. It was by far my fastest series, but other things factor into that. If you found an International, then I would unreservedly say you should get that, but I'm not so sure about a Competition. I would say a good rando bike is closer to a racing bike than a touring bike, but there are better bikes out there for rando than this.

You didn't really say what your distance goals were. I rode a full series on my gravel bike, and it is heavy. 200km on a heavy bike is one thing, but for longer rides it's going to slow you down.