If it is a GI model, upgrade it to Loaded specs from Springfield Armory or Brownell's.
I have the Loaded stainless and it is great, but could use a melt job. There are lots of sharp edges.
Factory stock grips with cross cannons are my favorite, I got them from Springfield direct. Rubber grips from Hogue are great when shooting a lot.
Wilson Combat 47D mags work great. But I also like the factory ones made by MetalForm.
"Loaded" barrel is match quality, I have great accuracy with mine, but I don't think it is a fully supported chamber.
Nice coating like Ed Brown or Les Baer have are very nice.
45 Super is pretty nice performance. If you have the Loaded (not Lightweight or other alloy model), you basically just upgrade the springs to run 45 Super loads.