My experience at this station was neither here nor there. It's easier on the eyes than Penn Station's Amtrak platform, for sure.
Here's my primary complaint: There are no signs on the street helping you find it!! Gare Centrale is under 2 blocks from either of two Metro stations. Not once from walking out the Square-Victoria Metro station were there any signs for which direction the building was in. We just exited the Metro and stumbled around... there are few people on the street to ask so early on a Sunday.
Only when the building was directly behind (no big entrance, but a subtly marked door...) did I have any idea it was there.
Montreal - put up some signs for this major transit hub, please! Your visitors will appreciate it.