Agent-J:
Just personal opinion, but after over 50 years of firearms ownership I prefer TDA (Traditional Double Action).
I'm of the opinion, (not necessarily shared by many) that a NON-leo type person is better served with the heavier first double-action round, followed by the rest of the rounds being of the lighter trigger pull SA.
If a person is NOT a "gun-nut" (I am) and has no intention of regularly practicing with his/her self defense firearm, no matter what the reason, then that person needs all the help he/she can get from the possibility of an accidental discharge (AD).
A pistol of the TDA variety with an external safety offers the person with limited firearms experience or skill this help.
I would suggest that 99% of those of us who carrie a concealed firearm for personal protection NEVER have to use it. So if this is true in your situation you'll be carrying that loaded firearm for days, months, even years never having to use it, and when and IF such a situation occurs you don't want to shoot yourself in the hip/butt/leg, etc. trying to withdraw it.
I'm also of the opinion that if you ever shoot someone your life is going to be changed FOREVER.. No matter that the person was a threat to your life or the life of your loved ones or innocents, once you pull the trigger you had better have a good lawyer standing by the phone, and even if the shooting is judged legal you still stand an excellent chance of being sued in civil court by the person, or his family if he/she doesn't survive the shooting.
And by the way, IF he doesn't survive the shooting, you'll be amazed to learn he was an altar boy, choir boy, Eagle Scout, straight "A" student, or spent his spare time feeding the sick & hungry.. Or at least that's what HIS lawyer will be declaring. If you think just because you were justified in defending yourself with potentially lethal force don't be sure the 12 folks on the jury will necessarily agree.. Juries are funny..
So, with a TDA firearm you MUST overcome a heavier trigger/striker pull on the first round vs the lighter trigger/striker single action pull. You WON'T be shooting him/her by accidental discharge because your adrenalin rush, or "fight or flee" reflex caused you to apply 4-5lbs of pressure to that everlite "Glock or Glocklike" trigger when it was not necessary to do so.
IF you have no choice but to pull the trigger just apply more pressure the first round, and all other rounds will be the same.. Lighter.
Personal confrontations occur up close and personal, are resolved with few rounds fired. The key for folks like you and myself IS to have a firearm available to us, and to practice with it often enough to be proficient enough to defend yourself with. Trouble is most regular, non-leo's don't practice much after the initial excitement of buying a firearm wears off.
Trust me on this.
I've had a lot of pistols/revolvers over my decades of firearms ownership and I've had the Glocks and even the squeezecocker (P7) and I always wind up back at the house of TDA.
Everyone has a favorite firearms manufacturer. I think the best firearm for a person is the he HE/SHE feels the most comfortable and proficient with. You will need, if possible, to shoot whatever pistol/revolver it is you are considering before you decide. Often a gun that "feels good" in the hand, simply doesn't translate when you have to actually shoot it.
So, the answer I suggest is TDA.. Practice often at self defense distance (7 yards or less.. I practice at LESS most of the time). Practice "point and pull" tactics and get help from a friend who is proficient with firearms, or even go to classes and have a profession instructor work with you if possible.
Just telling you like I'd tell my Son. (And have, actually...
)
Best Wishes,
Jesse