If it's a good cut, well seasoned, and cooked just right - I don't need steak sauce.
If it's just your run of the mill sirloin from the grocery slapped on a grill until it's brown on both sides, I tend to cover it in A-1. That said, I'll find excuses to eat A-1 because I love the stuff... Put it on bread, etc.
Not if I'm in a good steak restaurant, but occasionally when I throw a Kroger grade steak on the indoor George Foreman grill I'll resort to the A-1 or the Heinz 57. If I buy a good cut from a meat market I'll invest the time and care to prepare it correctly, and I'll make my own pan sauce to go along with it usually.
I very rarely have sauce on steak, as I either order the filet or a T-Bone, but HP sauce on a bacon sandwich now that's another story.
BTW HP sauce is from England and in my opinion it's much better than either Heinz or A1, it is however slightly thicker and comes in 2 favors here (Brown and Fruity) and you can get it at Marsh or Mierers, give it a go let me know what you think.
I live 5 mi. from a country butcher shop. They have some good steaks. I taste the cut first, and then add a little if needed. Like the taste of good beef, with nothing on top.
my wife always uses a-1, i only use it on hamburgers occasionally. i'd rather do a compound steak butter if i'm on the grill, or a red wine pan sauce if sauteeing. also enjoy lea & perrins, but i will take a shot of that straight up, so i understand if it's not for everyone.
a-1 and other thick sauces ruin it for me, but the mrs. likes it. i give her some grief over it, but i would walk out of any steakhouse that wouldn't bring it to her. our $, our choice of sauce.
I love A1, depending on cut, I'll occasionally use it, but I like it better on burgers. When I grill burgers at home, I mix A1 in the burger before I make it into patties.
If you need to mask the flavor of the steak, then steak sauce is okay. HOWEVER, if it is a top choice cut of meat, don't ruin the flavor of the meat. Otherwise, if you can't do without the A1, just get a chopped steak (ground beef) and save the dollars.
I'm more of a 50/50 person. If I grill it myself, than 90% of the time is no. If going out to chain restaurants I usually ask for it just in case, as most don't cook or season the stake right. But with that said, the best stakes I have ever had was #1 in Panama City Beach, FL at a place called Angelo's, the other was in T.H. somewhere downtown in a old brewery. I was in town working at the power plant but don't remember the name of the restaurant, but it was good.