I have an SPS in 204 Ruger with over 3000 rounds down the urethra and with the right bullets, it is still a sub-MOA gun (just).
Bolts/actions are 100% remingtom 700, just not jewelled. Factory triggers are 100% crap until adjusted, barrels and stocks are cheap - just like intended.
They are a capable off-the-shelf gun as-is, but form the basis for an excellent frankenstein due to their compatibility with SOOO many accessories. There isn't a 700 action that aint crooked, and Remingtom proved that a shyttey cheap barrel can still shoot reasonably well in spite of having huge run-out and a host of other factory flaws. A blue-printed SPS with a custom barrel costs less than a 5R milspec and will shoot at least as good or better