St Pancras looks pretty much like a shopping mall with the platforms a rather inconvenient addon.That concourse does feel like a bit of an afterthought in the context of the rest of St Pancras.
The most annoying thing is it's easy to go through the wrong gateline and then your travelcard won't operate the barriers on the correct gateline because of the software to prevent multiple passengers using the same ticket.Paddington platforms 13 and 14 for me, a long walk into a dungeon!
Sometimes I don't bother with them, wait for next train from the main concourse.
A heck of a lot more conveniently located than the old 'King's Cross Thameslink' station on Pentonville Road is the resounding answer to that rhetorical point (quite apart from there being far better space, access snd so forth).ps The first time I went there after the rebuild it took me a while to work out where the Thameslink platforms were.
I'm amused Kings Cross hasn't come up - imo it's quite a good station, even in the rush hour.
Waterloo: the new international bit did make it a lot more bearable, but the connection below level to the Underground is often not open at the moment, and there is a very narrow set of stairs which I'm sure will become a bottleneck in future.
Canada Water: don't remember it being too bad, but there is not a lot of space so I can well imagine it could get very choka.
Finsbury Park: a mess. Not a lot of space and it's a bit like a scrum with everyone going in different directions.
Bank (Northern Line): not too bad, but you'll have to queue. Quite civilised usually!