The Northeast Corridor Amtrak route is fine. The Acela trains are nicer and a bit faster but IMO not so much so that I typically will pay out of my own pocket at 2x the price. (The pricing is really for business travelers for which they only really need to be competitive with air.)

I much prefer those routes to flying. But Penn Station in NYC really is a disaster. (It's a long and sad story dating back to the Penn Central bankruptcy.) Although things are slowly being fixed up as part of a massive building project.