My Buddy used to shoot Springfield TRP model...and its the only 1911, that I have ever seen break a sear spring. He thinks it broke at around 100,000 rds....
I have a few 1911's...and the one with the highest round count ..is around 125,000 or more now....and I've never broken a sear spring.
I only use Wilson Combat springs in my guns ( not Ed Brown ) ...but I suspect both Wilson and Ed Brown springs are probably made by Wolff.../ but I would bet that Wolff makes or supplies springs to Springfield as well... so the spring you bought from Ed Brown is probably the same as the one that came in your gun ( and yes, you will have to tune it when you replace it - sometimes they are close right out of the package, sometimes they are not -- based on a few that I've had to replace for friends over the years )...a couple were rusted ( in used or abused guns ).