Looks like On the beach has given you some good experience knowledge there.
He was talking mostly about Heavy jets with the speeds, and I agree with him on the numbers, Medium jets will be far slower for example, LOT's E170 and E190 often fly around in the low M.70's so try to get a feel for you traffic and its performance. No harm in asking pilots what works for them to learn what you are dealing with.
Good Luck.