Paul kgyy wrote:
When flying IFR with jet aircraft, the pilot has little discretion
unless specifically given by ATC.

Jets are given pilot discretion clearance whenever possible. It is not
a rare event.

A usual transmission is, United xxx, descend to 15000, and that's what
you do. On rare occasion, it may be a little looser, United xxx
descent at pilot's discretion, cross intersection xyz at 15000.

You have that a bit wrong. If a crossing restriction is included a
pilot's discretion descent is implied.

AIM Reference:

If the altitude information of an ATC DESCENT clearance includes a
provision to “CROSS (fix) AT” or “AT OR ABOVE/BELOW (altitude),” the
manner in which the descent is executed to comply with the crossing
altitude is at the pilot’s discretion. This authorization to descend at
pilot’s discretion is only applicable to that portion of the flight to
which the crossing altitude restriction applies, and the pilot is
expected to comply with the crossing altitude as a provision of the
clearance. Any other clearance in which pilot execution is optional will
so state “AT PILOT’S DISCRETION.”



If you want a better feel for what actually goes on than you will ever
get via newsgroup, take a couple of United flights and listen to the
ATC channel - it can be much more entertaining than the movie at times.

If someone has to ride United Airlines to learn about ATC transmissions,
the pain isn't worth the gain.