Originally Posted by elcruxio

9 minutes is plenty of time even when you need to get 2 fully loaded bikes up and down a flight of stairs cause the station has no elevators. But sure, I've seen examples which would not even fit into a train (well, they might fit into a Finnish night train but that's pretty exceptional in terms of space). I guess I advocate a maximum amount of luggage one can comfortably carry up stairs (in my case 120lbs of bike and gear)

Same as above

This has more to do with gearing in my opinion. I push the same watts whether I have all the gear or no gear on my bike. It's the time I spend going uphill that changes but since I don't have time limits it doesn't matter.

More comfortable? A loaded bike does highlight a bad fit the same way a trainer does, but if said fit is in order there should not be problems.
Luxury items are of course subjective as are certain necessities (I had a rackpack full of medical supplies for example).
There are also bonuses to a bit more load on the bike, like the missil'esque descending properties a well balanced bike gives.