Boots every time. Good pair of shock absorbing insoles-changed regularly- thick, good quality hiking socks-keep your tootsies cosy, sweat and rub free- and a liberal spray of shoe deodorant at the end of the day.
As soon as your boots start wearing out, order a new pair. Railway procurement takes a long time, especially if you have tiny feet, like me. My boots are a size bigger than my normal size to take into account insoles and socks too!
Carry, or have quick access to, a spare pair of laces. Life saver! Break them in well and apply a good dose of waterproofing or polish too.