normally i prefer alone, in 3/NV i didnt use companions at all (in NV i had boone on a couple of my 1000000 playthroughs just cause i liked him)
but in 4 i find i have to purely because all the junk is useful and the insane weapon weights and i need their storage space.
i like having piper around though she is amusing and cute
problem is (well in my game) they just keep either teleporting or running off somewhere then run back to me, this cause all sorts of issues in the dungeons as say i can be on level one sneaking around and then all of a sudden i here a big gunfight happening which is up on level 3 and its my companion who has just teleported/run up there for some reason then tried to come back down to me. is very frustrating as im stealth build and i cant play that way most of the time due to companion setting off whole area stupidly like that.