"Upgrade" to Ultegra R8000 from 10-yo Campy Chorus?

[beeatnik]

Tho I prefer the "tactility" of Chorus 11, I'd try R8000 for a winter bike. The crankset should be stiffer and you can get mid-compact chainrings. The brakes are superior and provide more clearance. Finally, the Ultegra cassette is a bargain and is available in 11-28. As for front shifting, R8000 has a lighter feel but IMO properly set up Campagnolo 11 is as fast.

[DJT21]

It sounds like your shifters need a service; strip them, clean them and replace the G springs. That should solve your shifting issues.

Try doing the same with a Shimano groupset ten years down the line

This is 11 speed. 11 speed shifters do not have G springs.

Setting up a Campag groupset is no more difficult than doing a Shimano one.

Yes, I misread the OP.
I've never used 2009 Chorus, although I've owned/used Veloce & Centaur Ultrashift from 2009. Both were a bit wishy-washy/vague; they changed the mechanism and cable carrier in them at somepoint around 2010, these later ones were much better (then they changed them to Powershift).
A tighten up of the bolts front & back of the shifting mechanism might help, as these sometimes loosen off.
Otherwise, replace the right hand shifter body itself? These are around £70, but you need to fit your existing brake lever/bar clamp/hood.