I agree with NGIB, if you have a short barreled model, you definitely need to change them more often, but 800 seems low to me personally unless you have been shooting a heavy diet of +P
I had a full sized Kimber 5" and put a one size upgraded spring in it per Kimber's specs ( I can't recall the weight but Goju can tell you
) right out of the box to accommodate for the +P ammo I wanted to shoot and carry. This was after a phone call to Kimber about running +P ammo and I bought it from them at probably twice what I could have got it from off the internet but it was my first 1911.
I changed that spring out once around 2000 rounds out of paranoia, but I never noticed a decrease or any type of failure with the weapon.
As with any weapon, it's good to check out all the moving parts and "know" your weapon. What is the weight of the spring now? Shoot 500 rounds, pull the spring and see how much weight it takes to collapse it. If it's less than before, think about changing it, if it hasn't shown any wear, repeat at 1,000.