In mid-June, we are taking the early Eurostar from "London to Any Belgian Station (via Brussels)", then heading immediately to Bruges. On the same day from Bruges, is it best to get to Amsterdam via Brussels or via Ghent/Antwerp? Being it's the same day, I think Eurostar ticket would include our ticket back to Brussels from Bruges to get on the Thalys to Amsterdam, but we wouldn't mind the extra expense to at least pass thru Ghent and Antwerp if it didn't take too much more time, as this will admittedly already be a very long day either way. What would you recommend?
Eurostar "to any Belgian station" means just that. It is a ticket to get you to a destination, not a pass to get you there and back.
You can go A-B via C, so London to Bruges via Brussels; you are not allowed A-C-B-C.
You are not planning to get off the train and look around in Brussels, Ghent or Antwerp, are you? You don't have time for that.
When you say that you are taking the early Eurostar from London do you mean the 0650, the first one? Even that doesn't arrive in Brussels until 1007, and the first reasonable connection to Bruges is at 1051 but if you are quick you may make the 1022. Either way you don't get to Bruges until nearly noon.
If you fly around the city in 2 hours including to and from the station (you will see virtually nothing - far better for a flying visit would be 4 hours) you might be on a train towards wither Brussels or Antwerp around 2pm, barely enough time to get to Amsterdam. You certainly have no time to stop anywhere.
Thanks for your reply Nigel! We were not planning on spending any time in Ghent or Antwerp, just passing through, mainly just to see the Antwerp train station since it's supposed to be a spectacular sight. Is the train route to Amsterdam via Ghent/Antwerp more scenic than via Brussels? Will it take more time?
With the quickest train connections you will not have enough time to see the Antwerp railwaystation. If you take the intercity train to Antwerp you likely arrive at the highest floor, will see a bit, but have to use that bit of time to go to the lowest floor, deep in the basement where the Thalys departs. However train connections with a 4h duration (Bruges – Antwerp – Amsterdam) will give some twenty minutes to change trains and so a bit more time to see the railway station in the proces. If you think to need more time, take an earlier intercity train from Bruges, but keep in mind that you have to pre book your seat on highspeed trains and show up right on time printed on the ticket.
If you travel via Brussels, the Thalys will stop for a few minutes in Antwerp in the basement, from there you will not see what you want to see, except a lot of concreet. The routes are not directly scenic to my opinion.
Re-read Nigel's excellent reply. There are vast numbers of unreserved local trains between the Belgian cities you list. But your Amsterdam leg has far fewer choices. This, along with reasonable allowance for train lateness, will be the controlling factor.
BTW, the Bruges RR station is not "at" the medieval-town. The bus takes 10 minutes or so, or you can take the long walk.
If possible, stay overnight in Bruges, to get more out of that stop. Choose your Bruges-Amsterdam train route based on a balance of the most convenient schedule and price, such as:
3 hours with a connection at Brussels to the expensive Thalys train
4 hours with connections at Gent and Antwerp
5 hours with a connection at Brussels to a cheaper InterCity train.