In the old days, bolts were tightened until they were tight. Now we have TTY and a bunch of other ******* fasteners that require 10 times the breakaway torque that a normal fastener should. 6 point has the best chance of removing a fastener.
12 points are more likely to round the corners of a bolt. Especially if the corners have started to round. So 6 pt. sockets do have their place.
If he has a modern 12 point sockets (Bonney Loc-Rite, Wright Drive, Snapp's Flank Drive, etc), rounding a fastener is very low. Put a 25 year old Bonney on a fastener and see how far in from the corner it is biting the flat....far enough in that it isn't going to round the fastener.
Furthermore, if he wants the 6 pt because I wants to match his deep set's 6 pt and waste money, fine, buy a Snap On or Wright or SK and be done with it. However, it seems to me by reading the first post, he just "noticed" by looking, that his set don't match each other in how many points they have (maybe he should get the same brand as the 6point set so they match each other

)....so why waste your money on something not really needed when he could use it to upgrade something else?