OK, tell us all about "SRS" then. Of course, in an Airbus it has a different meaning!
But...our Ops guys are usually pretty good. A slightly late slot is 100 times better than one which allows for a 40 mins turnround, with 220 pax both ways and a long taxi.
I have to admit that we usually tell our handling agents that we will be on stand about 10 mins before we really will be and tell Ops that we will be on stand 5-10 mins after we will be. Then it all usually works really well!!
And how does the extra 10 mins work? (Not the ATC discretion 10')