I got a shorter stem and flipped it, and went with bullhorns.
That let me move my saddle back.
I like the stock saddle, except for the weight; still, it weighs less than a Brooks.

My Pista's stock wheels have eyelets and weight 405 grams.
If they don't fail, and they show no sign of doing that, how can I improve on that?
DT Swiss RR 1.1 rims weigh 415 grams and would cost a pretty penny.
As long as my present rims don't fail, I can't see replacing them.

My stock headset didn't make it a year.
I've replaced it with a Chris King headset.

I also bought a couple of Sugino/SR chainrings and EAI cogs from Sheldon Brown and with the chainrings in the outboard postion and the cogs installed with the flange inboard, I have a remarkably perfect chainline.

I also upgraded my pedals to double-sided Shimanos.
They probably weigh a little more than the stock double-sided pedals, but they work beautifully.