Don’t forget to factor in all the additional time getting to the airport and dealing with check in and security.
I went by train to Germany during the autumn of last year and oh man, what a pleasure it was. I got there about 5 minutes before the train, got in, dumped my suitcase and had room to spare.
During the trip I sauntered between carriages, bought some (mediocre) food to scoff down in the restaurant carriage, which I opted to do at my seat rather than right there because I felt like some quiet time rather than the buzz.
Later I traveled by plane to Spain in the spring and as nice as Barcelona was, I couldn't say the same about the plane trip, which was a necessity rather than a pleasure.