The benefit to a lighter weight bullet is to get more slide speed at the same power factor. 150 pf is pretty low for 45 Auto. I am going to try some 200 grain bullets this year for that same reason.
I have had much better luck with round nose bullets in my 1911s, so if my 200 grain SWCs don't have the reliability I'm hoping for, I will be shooting a true 230 grain round nose bullet, which is historically what I've shot in Wild Bunch. I am going to be backing them down a bit as the ammunition I was shooting last year was loaded to ~170 pf. I had backed it down some from my typical load but I'm going to lighter springs and a significantly lighter load this year and dropping down to a 12.5 pound recoil spring. If you're shooting a stock 1911 with a 23 pound main and 16 pound recoil spring, you're going to want to load to a higher power factor, as the 1911 is designed for 195 power factor ammunition.
I recommend the fastest powder you have in inventory, in this case, Titegroup, although many people say not to use it with coated bullets. I have not ever loaded Titegroup in anything so take this advice for what you paid for it. I was using Clays powder last year, I may continue to do that if I have enough left or switch to Clean Shot or WST.