QE2 and QM2 - both of which have promenade decks - do not have muster stations on deck. This is understandable in that in the event the lifeboats needing to be lowered, it would be easier if there were not passengers in the way. Also, I suspect that the crew assigned to muster stations find it easier to ensure that passengers do not 'wander' if they are located within a 'room'.
I, too, find that pre-arranged times for a muster drill does not demonstrate that the muster will go according to plan. But then again, the chances are that *something* is going to get in the way of a muster be it for practice or for real and trying to make the muster as realistic as possible would require many executions. Imagine the mayhem if they did a drill in the middle of a formal dinner? That would go down like a lead balloon. Or imagine that they did a 'trick' and said - sorry - the port side of the ship is a 'no go' area - you'll have to find another route to your muster station under emergency lighting only. Both scenarios are quite realistic.
The crew on Cunard do practice lowering lifeboats, and sometimes an actual 'depart and search for survivors' exercise when the lifeboats are lowered, detached and then circle around some distance from the ship. Quite interesting to watch if you're in port that day....
It's SOLAS regulations that insist on a muster drill to be performed for all *new* passengers joinng a ship that they will be on board for for more than 24 hours, and within 24 hours of departure.
Muster drills go some way to ensuring that passengers (and crew) can at least adher to the basics of getting a life jacket and get from their cabin to their muster station. IRL, the whole process could take considerably longer - especially if the event which triggered the muster was sudden and severe.
However, as in staying in a hotel where you are not required to attend a drill, there is nothing stopping the sensible passenger from thinking how they may best react in the event of a muster being called out of the blue. When you're lying on the sun deck - imagine what you would do to get to your cabin and find lifejacket. Do you really know the quickest safest route? What would you do if that route was unavailable?
On aircraft they request that you pay attnetion to the safety/emergency demonstration. Few do - and tests have shown that those who DO pay attention, and furthermore, those who think *beyond* what they are told, are the ones most likely to survive an emergency situation. Eg. In an aircraft - you *should* look for which exit is nearest. Are there any obstructions on the way to that exit? Is the waif like female cabin attendant going to be quickest to open the emergency exit on the left side or the muscular man with nobody in the adjacent rows on the right hand side of the aircraft?
Plan ahead -and stay alive. God forbid you should need it.