I used all of them, but efficiency wise, Annie and Vette beat them all, by far, for several reasons:
1 - obvious, loading capacity !
2 - utility slots : not only you can decorate them with zillions of heatsinks, allowing you to spend years in the oven inside, but you will never run off them.
3 - NOT just passengers : you can "clean" all the items floating inside very fast ( escape pods, black boxes, materials, etc ) since you can allow a pair even two pairs of collector limpets AND you still have room for 32-64 tones of cargo for those items.
To Conclude:
EACH trip should get a "score" based in the numbers of "stars" you can get per trip. Small ships will get half dozens of stars, more or less; medium ones, like Python, 20-30...
But the Vette and Annie will beat them all with 40-55 stars / trip ( you get 20-30 from passengers rescue and 25-30 MORE from the missions given by the rescue ship where you unload the passengers ;
That is, you can "rush the grind" from low rank in Empire / Fed in just a few hours of intense gameplay. What will usually take days or weeks, with a Annie or Vette can be done in hours, in this rare, particular occasion.