If you're flying 50 times a year for business, lounge access may be worth substantially more to you than if you only flew a few times a year. Not to mention if you're going to be flying 50 times a year, that $560 means ~$10 per flight to make your experience substantially less awful.
I don't fly internationally much, so most of my flights are direct. Is it mostly for layovers?
Peace and quiet is a second benefit. If you're waiting a couple of hours whilst sleep deprived (often the case for business travel or when booking budget flights that leave at 1:30am), those loud, constant announcements are very annoying. Bonus points if the airport has terrible seating and the lounge has comfortable sofas. If you need to work for a bit, it's a great place to do so, especially in airports that don't have free WiFi (increasingly rare these days).
The food is rarely good in Asia (at least at those lounges I have access to). Reheated noodles and some meat if you're lucky and flying at the right time. It's convenient, at most, saving you the trouble.
It really varies by city. HNL and NRT have terrible lounges for PP card holders - basically a room where you can sit for a while, sometimes with a free beer (but there is a great sushi-ya just opposite the NRT lounge). GVA has my favorite ones - nice view on mountains, usually empty (except if Aeroflot is flying soon...) and a decent breakfast with muesli and fresh bread and pastries. SIN lounges often have free massage chairs. Which are available for free in T3 as well, but it saves having to take the monorail there.
On timing, if you are flying long haul you can face serious delays (like a huge queue at check-in and security) and need to pad it by a couple hours. Most of the time, you don't face these delays and have a spare hour to kill, and in most airports the lounge is a better place to do so. Sort of applies to short haul too; I once missed LHR-GVA check-in on BA by a single minute and they were very annoying about it despite the empty airport (had to book another flight).
I scored a mid-level membership once. I didn't go out of my way to do it. Nothing super good about it.
Oh, your luggage gets a priority tag and comes out first. In certain airports that can save an hour of your life.
But mostly its about accumulating miles on trips I'd be taking anyway. Essentially free upgrades, or entirely free flights. Just for joining their silly program. Why not?
I do the same with hotels.
The next time, it won't work so well.
The next time, it won't work so well.
The next time, it won't work so well.
And down the path you go. Up the dose, etc, etc.
Don't use valium unless you have a real and only very occasional use for it. And try to keep that in mind: it's a use case. Not a need. You never need valium. You need food, and shelter from weather. But you don't need valium.
At the higher I didn't notice any effect, until the plane started bouncing, and then I realized I didn't care, which was perfect. I didn't notice any drowsiness at that level, which may have been due to adrenaline.
Over the course of 6 years, my regular dosage approached 50mg as I kept upping it whenever I started to get nervous flying. If taking it while I got on a plane, I didn't feel drowsy. It became not always effective.
About a year ago I made a conscious effort to wean myself off it over the course of 12 weeks, by flying a return business long-haul flight every week, and taking a little less each time, practicing the principles in Dr Claire Weekes "Freedom from Nervous Suffering" (essentially breathing exercises, although it's a little more nuanced), which is in fact a book for agoraphobics which someone had suggested to me. I got down to zero, but found under 10mg then turbulence still had fairly heavy emotional and physical effects on me.
Now I take 0-10mg when I fly. I don't notice any effects, other than I am less sensitive to turbluence. However, I exclusively fly business class rather than economy, which I suspect helps a massive amount.
During this time I also tried Propanalol at some high doses. I found it ineffective for fear of flying, but very very effective for giving presentations. However it started to make me short of breath, so I ditched it.
In terms of intoxicating yourself for flying, I have found Ambien to be highly effective. However, it seems many many people have bad side-effects from it - sleep-walking, etc - so unless you're totally certain you can handle it well, I don't know that I would recommend it. These days I'll settle for 10mg of valium and some alcohol.
Maybe the idea was to help with the culture shock in the same way "getting jumped in" helps you adapt to gang-life.
I have resigned myself to never taking a first class reward flight because I can get at least two economy trips with the same amount of miles. I just can't justify that to myself, despite the (more than 2x) dollar amounts attached.
With security this meant getting up at 4 to catch a 7:30 flight, to get to the meetings by 9:30, all day in a conference room, leave at 5 to get to the airport for a 7:30pm flight to get home by 9:30 or 10:00pm.
Flying business class changed the whole dynamic. I was fed a real breakfast in the morning instead of getting the shakes from a relatively empty stomach and too much coffee. I got a hot towel to wipe my face with and feel human when I showed up at the meeting.
On the way back a light dinner and a glass of wine with a little elbow room.
The extra 30% for business class was well worth it.
If I was staying overnight, perhaps not.
(am also nearly 2m tall.)
Why would this make sense? Surely there wouldn't be a benefit worth more than $560?