I have enjoyed the well-priced, excellent service of the Amtrak Downeaster between Boston and Maine as well as Boston to UNH-Durham business trips. I have found Amtrak staff on state corridor routes such as Shore Line East and Downeaster to be very friendly, just like you imagined train conductors and staff to be from old movies.
Downeaster vs. driving
I am guessing that round-trip service from Boston, MA to Rockland, ME would be about $65, and take about 3 hours 45 minutes one-way. The driving time would be the same as the train, maybe more with a car due to rest breaks and traffic.
Rockland, ME is in Lyft’s Maine service area. I would guess that on summer weekends, there would be a couple Lyft drivers active, particularly if Amtrak came to town.
NNERPA’s proposed Rockland, ME service was thrice-daily round-trip service on summer weekends. However, Amtrak declined to evaluate such service, preferring instead to consider more frequent daily round-trips in summer 2019, with tentative track evaluation later in summer 2018.