As a more or less UL hiker, I've never understood the role of a fleece jacket. It's too warm to hike in most of the time (a rain jacket or windshirt usually works fine, and my rain jacket and windshirt combined weigh 3 oz. less than the R1. If I wear both together, I can hike down to well below freezing comfortably). But a fleece is not as warm as a puffy jacket, which will serve you better for hanging around camp or sleeping and probably weigh less than the R1 if you get a lightweight model.

The R1 sounds like an improvement over the wool sweater, but if you really aspire to go UL, you can probably do better. In the future, I would suggest thinking more about clothing systems (like a windshirt + rain jacket) and less about replacing individual items.