As a regular SLF I sometimes watch the briefing, sometimes do not. The most important reason for not watching, apart from having better things to do (papers, book) is that, although the flight crew claims that all aircraft are different, the briefing is *always* *exactly* the same. In fact, I think if the flight crew is one person short, they can randomly select a frequent flier (best chance in business class) passenger and he/she will do a flawless briefing with all the proper motions. I know I would, since it's all the same:
Every aircraft seat I've sat in has been equipped with a seat belt. I insert the flap into the buckle and then pull on the strap to tighten it. I lift the flap to undo the belt. The seat belt is mandatory during taxi, take-off, landing and turbulence, and a good idea at any other times. Also, on each and every flight, during taxi, take-off and landing my seatback had to be in the upright position with the table folded away.
On each and every plane I've been in oxygen masks will fall from the overhead panel in case of a loss of cabine pressure, and I need to pull the mask towards me to activate the flow of oxygen and put the headband around my head then pull the loose ends to fasten it. Then I help others.
Each and every time, my life vest will either be under my seat or in the center console, and I need to pass it over my head to put it on. Then there's a strap around my back fastened with buckles, and two tabs which I need to pull to inflate, but NEVER IN THE AIRCRAFT. Oh, and did I mention they had a light, a whistle and an oral inflation tube every time? Again no differences here between airplanes.
In case of evacuation, each plane has floor lighting that leads me to an emergency exit. Each exit has a huge red handle which says "pull" and if you do that, it opens. Also, I know about the brace position - it's the same in every aircraft.
Equally, every plane has a safety card to review at my leasure. Yes, I take a look at it but that's because I have an interest in the design of these things.
I am security conscious despite not listening to the briefing. I do take a look, as I get seated, where the emergency exits are, and I count the rows from my place to the nearest. I leave my shoes on until we're safely in the air, and I put them back on before we land. If I ever get seated on an overwing exit and there is an emergency, I know I'm not going to open and take out the door, and then leave it on the seats for my fellow passengers to trip over (as advertised in the safety card) but I'm going to throw it out through the exit to get rid of it. I know I'm not going to take any hand luggage with me and I'm going to punch everybody in the face who does and hinders my exit. I don't wear high heels but if I ever do I promise to take them off before I jump on the slide.
And as for the slides doubling as rafts, well, I'd like to see some statistics on the number of cases where this has actually worked. I don't have high hopes though: I've seen what it takes for an amphibian plane to land on water without damage, and that's a plane that's been designed to do that.
I don't know what it would take me to pay attention to the briefing every time. Perhaps what would make things more interested is if the crew would add a different safety tip in the briefing each time. Like the "keep your shoes on during the dangerous phases" thing - running over broken glass is much easier with shoes on. There can be hundreds of others and if you hear a new one with each flight, it might make the whole briefing more worthwhile.