Greetings JG1
Methinx (happily), you may be overestimating our skills and/or the equipment we work on.
I have no idea what the preferred speed/point for descent is for every a/c, you can only say from the feeling in yr butt that someone is 2 high / 2 fast. The only thing we need is everyone 2 b doing similar speeds when vectoring - i.e. 250kt inside 40nm and 210kt later. This makes 80% of the inbounds virtually the same for us.
You also need 2 remember that, to save frequency space, if nothing is said - it is expected that you do what is on the SID/STAR. If everyone was "Just asking", it could get out of hand quite fast.
As to the PCs holding next to the field, that's actually what we do, it's just not a published procedure. They r generally not held at the TMA beacons, but rather orbited on base if there is no space. This is done since the locals r quite adept @ ramming them in at max speed - they r as fast, if not faster than the jets inside 15nm!
Also, I'm not sure what BS the press releases have been saying, but there are no computer calculated anythings! That would be part of the SAAATS system, which will come on line in stages (read wait a long time for any benefits). All the decisions about sequencing, speed etc are purely educated guesses - and I must admit some blokes r pretty good @ it!
Lastly, methinx this kind of thread is gr8 for all aviation professionals using FAJS. We seldom get to yak to the tube drivers 2 get there points of view on our performance - and vice-versa.
So, keep the questions and opinions coming.