From nice to lucca

I always think for travel up to six hours or so the train is always best. What is the concerning about connecting through Milan?

Janis, Not all of the trains go through Milano Centrale on that route. For example, there's a train departing Nice Ville at 07:55, arriving Lucca at 14:47 (time 6H:52M, 3 changes at Ventimiglia, Genova Piazza Principe and Pisa Centrale, compulsory reservations on two of the legs). There's one shorter trip than that at 6H:32M, however it has four changes. I generally try to minimize changes if possible. There's also a train with only two changes in Ventimiglia and Viareggio, but it departs at 05:25! Viareggio is quite a small station so changes there are easy. When I was through there last September, it almost seemed deserted. The schedules I quoted are of course subject to change (but probably won't change much). Happy travels!