Faster ?
Shanghai Maglev 431kph / 232 kts
Shinkansen 359 kph / 194 kts
TGV 320 kph / 173 kts plus.
Twin Otter cruise speed at 10,000 ft 182kts , probably slower on floats.
Personally when in Europe ( and if I ever get back there ) I don’t bother with aircraft.
Trains are way easier.
Door to door it would be faster on the Twin Otter. A High Speed train isn't going to pull out of Central and start doing 300KM/H. Additional to that Trains don't go in a straight line so it would have further to travel.