Does this actually do anything? I haven't noticed a change in any of the protections when I pick their personality mode, they still just walk around and shoot/attack anything that's hostile

They will use different attack types... the First Aid one uses electricity, the Construction one uses a nail gun etc. It is mentioned in the loading screens about them.

I've had mixed results with this. I was in a hospital (don't recall which one) and I set the Personality to "police" and it still showed up as the standard Protectron medic. Other places I've done this have actually changed the paint scheme on it and personality, so I don't know if it was just that one area, or something I did on my part, etc.

I have found them to not be very helpful, and usually blast them apart. If a stray shot/explosion hits them, they turn hostile (for me) anyway.

if u're set him to subway stewart, he'll turn hostile. so you can kill him with every comp withot getting a dislike^^

Its mostly for there dialogue as I grasp it.

I've played around with it a bit and the only difference I've found is the weapon type that they use.

I usually activate them when I encounter them, but not until I'm thoroughly done with the whole area. Any kind of stray shot makes them go hostile toward everything, so I just clear a building it, then active the Protectron in the lobby or wherever. Hopefully they'll keep the raiders from repopulating a building that I've cleared out.

If you change the Personality you change its protocalls.

So if you change it to a Subway Protection, it'll ask you for your Subway Token, if you don't have a subway token it asks you to leave, and if you don't it attacks you.

I'm not too sure what each of the personalities will do as they are new to Fallout 4.

There are a few things you can do to get more use out of Protectrons.

1st there is the Robot Hacker perk, but its first rank isn't really useful.

There is a Total Hack magazine for Protectrons that is amazing, cant remember where I got it but it comes with a tape that will re-program the Protectron when you use it.

-VIP escort, makes the Protectron a companion until it is destroyed...Doesn't last forever but does work for a long time.

-Erase Targetting Parameters, makes it hostile to everything.

-Set Allied Status, makes it attack anything that isn't you.

Cant remember all of the things you can do but the VIP protocall is a lot of fun.

If you have Robot Hacker, you can sneak up on active robots to use your Total Hack tapes when there are no terminals around to use.

When killing them for their scrap be careful of the legendary ones as they will blow up like a mini nuke

My understanding is that if you use a default personality, it will just walk around and use Melee attacks, and possibly lasers (these may be built into every model). However, if you use the proper personality profile, it will unlock other attack options. The Construction version, for example, can have a Nail Gun, giving it a ballistic ranged attack, while the Medic version gets electricity-based Melee damage. I haven't seen loading screens on the other types, so I can't tell you what they do, but I imagine that there are benefits to each. I could be wrong, though. As a general rule, I don't bother activating Protectrons, as I'd rather kill stuff myself.

Set them to construction mode while wearing a hard hat. It is very minor but cool at the same time.

Wearing different outfits could effect the dialogue further but have only discovered the hard hat one.