I've given up on Roman, he's a pain and a pussy and I never use his free cabs anyway.
Brucie is cool shit though because you can start a fight with a bunch of people and he'll have your back.
Little Jacob is useful as hell because once you get further in the game getting body armor and kick ass weapons helps a shitload before starting some of the missions. Though I honestly don't think I ever took him out, I did maybe 2 side jobs for him and it unlocked the weapons