My daughter and I flew into Boston last September instead of Portland to save $$. Never again! We fly out of Baltimore all the time and I really like the airport. I understand the hassle of a connection but the Boston traffic and rental car hassle, in my opinion, will be worse.
At Boston, you have to take a shuttle to get to the rental car pickup place. It took forever as you stop at the T-stop first.
Pro-tip - join whatever car rental club you can so you can miss the front desk (40 people in line) and head straight to the garage (only 5 people in line). We rented from Budget and got a Fastbreak membership for free.
The drive up from Boston is not memorable and the traffic could be horrible!
We flew into Portland in April and rented a car. Portland is a small, friendly airport. We were upgraded to a SUV (Budget again) that only had 40 miles on it.
We stayed in Freeport (visiting Bowdoin) at the Hampton Inn which is older but clean with good service. On our last day, we drove up to Acadia. We drove up I-95 and back Rt 1. All you see on I-95 is lots of trees. It is a really boring drive. Rt 1 is gorgeous but could have bad traffic in the summer.
In September when we visited Bowdoin, we drove up Rt 1 and had a long traffic jam entering Wiscasset from both sides. There must be a really good lobster roll place (Red’s Eats) as the line was down the street.
Acadia in April was gorgeous. We lucked out on the weather and had a sunny day in the 60s. The town is very small and was crowded in April. I can’t imagine what it must be like in the summer. A friend of mine said that they rent bikes and take the tram everywhere so they don’t have to worry about parking. Probably depends on your level of patience…
I think lots of Maine coastline is just as beautiful as Acadia. Acadia is beautiful but I don’t think it would be worth dealing with crowds if you can see similar scenery without them. (Unfortunately I don’t know if this is true). My daughter and I enjoyed the challenging beehive trail hike and Jordan Lake was pretty. And while the view from Cadillac mountain was impressive, I wouldn’t do it again.
In South Portland, we drove to 3 lighthouses, Bug, Spring Point Ledge, and Portland Head light in Fort Williams Park which were all amazing and different.
Maine is a big state with amazing and diverse scenery from the mountains in the west, lakes in the center, and the beautiful coastline. Have fun!