I play a healer and I only group with guildies who are cool with me rolling for an item for my companion if it is an upgrade. I know others may not be cool with it, so I only heal for friends. As a sith sorc healer, I am severely gimped solo without a decently geared Khem Val. Sometimes, Khem is our tank so it works out to everyones advantage when I have him geared well. I spend alot of time artificing, checking the kiosk and farming commendations to get him geared appropriate to my level. If an item pops that is better than I have on him to upgrade, ya I"ll roll need but it's rare. Now that being said, I only use Khem and I'm level 48. Khem and I are essentially siamese twins, which is... sorta creepy but it's the way it is. I don't on items that aren't his class, or items to gear other companions to strip down.
So, yes I will roll need on an item that is not of my player class, in specific circumstances. I won't roll if I know it's a great upgrade for one of my friends.