Ah Ha! Well ..... Humpff!! Let us remember an "X" is just a has been while a spurt is just a "drip" under pressure. However, let me elaborate just a mite. A caveat. I've set up a pile of SAs over about 18 - 20 years a CAS Gunsmith. I are opinionated (so I've bene told) so I will attempt to separate personal opinion from known fact.
Out of the Box, your Pietta has the best of the flat Trigger/Bolt springs out there. It does not need to be replaced. It is springy enough to raise the bolt smartly yet light enough not to beat the bolt into the hammer notches and peen the edges. Personal Opinion: Works well enough to use in action jobs and gives a nice "crisp" feel to the action. Wire springs are nice. I don't care for them. To me, they impart a somewhat mushy feel to the action. Last mostly forever though. The wire spring may need a little fitting.
The Pietta Main Spring is ....... KRAP. But .... so is everybody's. You actually have three choices for a Main Spring. Your looking a Wolff and they make a nice spring. Personally, I don't like it. It will take some fitting. there is actually nothing wrong with, it, I just don't like it. Your next choice is from VTI Gunparts. They market a rather nice Reduced Main Spring. May take some fitting up at the hammer. Last on the list and at the top of my personal list is the "Lee's Gunsmithing Gunfighter" spring "kit." Main Spring and wire trigger/bolt spring in the same bag. May take a little fitting to clear the hammer .
The spring from Wolff will normally ignite ANY primer. The springs from VTI and LEE'S may ........ not. Perhaps a preference for Federal primers will result. Your dime, your call.
Coffinmaker