I always stay on 95 until the exit for Coastal 1 near Brunswick. The southern portion of 1 is just urban sprawl and traffic. The further north you go the more scenic 1 becomes. Two lane and heavy traffic northbound on Fri, southbound on Sunday.
My dad lives right off US1 (Near Milbridge) and we visit him frequently. Last year, we pulled our 36' FW from New Hampshire to his house using US1, then up to Calais. We encountered a couple of minor road construction delays, but the highway presented no problems for us. We even saw a huge caravan of Airstreams heading up the highway.