I have to tell you that I am not and will never be in favor of messing up springs. I'd say to keep what you have or buy different ones but don't mess with what you have.
I don't know much about AR's but I've been working on rifles for about forty years, so I don't mind looking into something new. My DPMS carbine shoots and functions beautifully but has to hold the world's record for the most despicable, grunchy trigger.
I popped off the upper and yanked out the lockwork to take a look at it. Pretty straightforward, even simple. I polished the engaging surfaces with a rubber impregnated polishing wheel in a Dremel, just enough to clean up the surface without taking off any serious metal. Then I cleaned and lubed all parts and carefully reassembled, using generous amounts of Tetra Gun grease on bearing surfaces.
It's a BIG improvement and is much more pleasant to shoot. There still remains a very "tiny" amount of creep, possibly not noticed by most folks, but it is there. I will take a second look at it later and see if I can get the creep out of it. Otherwise.........a very worthwhile improvement. I NEVER want to shoot anything that has a trigger like this gun had.