I went to Belgium for work. I don't think there are many other reasons to go. I'd been to Brussels a few years ago, and not really found a whole lot to divert me. This time I went to Leuven, which was more interesting. But it was February, and it rained more or less constantly during my stay.
I stopped in Brussels on my way back home from Leuven. I got off in the centre and went for a quick look at the Grand Place, and I was going to walk down to Midi station but decided against it when it started raining heavily. I walked back to Brussels Central and got a train instead.
The Eurostar used to come into Waterloo Station. The terminal there cost a vast amount of money to build, and was then only used for 13 years. The new terminal is at St. Pancras, which cost an even more vast amount of money, but at least has a good chance of lasting for more than a decade and a half.