Originally Posted by
ja_user
There is sometimes also an advantage (and disadvantages), with respect to upgrades clearing and the number of stickers used.
Not to mention, with a single flight number, miles are earned on the origin to destination mileage.
STL-DFW = 550
DFW-SJO = 1776
But STL-SJO = ~2016
So you get 310 fewer EQM/RDM with the same flight number.