For some period of time, I used one load for everything, Clays at 1200fps with 8s. It was easy, simple, didn't have to think about changing bushings, just load and shoot. First shot of doubles with a PFS on my old MX-6 was no problem. In fact, that's the load I shot my highest doubles score with at the Georgia State Shoot a few years ago, a 96. No problem with 8s in handicaps as long as I was on or closer than the 23 yard line.
But, that was when I was shooting up to and including the 23 yard line. At 24 and farther, I wanted the 7 1/2s and at 25 and farther I wanted more speed, so I went to 1250fps shells. So, as long as I was changing, I went to 1 ounce of 8s for the first shot of doubles at 1180fps.
I know that there are some good shooters here that say one doesn't need 1250s, that 1200s will do fine at long yardage. I have tested (not nearly as well as Neil would have done it, but tested the best I could) 1200s vs 1250s. Sometimes I got as many hits per 25 with both, but, overall, I got more hits with 1250s than with 1200s.
Hence, I can't (or at least won't) use the same load for everything anymore.