Indexing, be it via downtube shifters or Ergo levers, is much more precise than friction shifters so just upgrading the levers would give a noticeable benefit.
If you want to upgrade further then the costs will mount as you'll need new hubs as a 10 speed cassette won't fit on an 8 speed hub. Campag hubs are either 8 speed compatible or 9/10/11 speed compatible as they changed the spline pattern in the move to 9 speed.
Personally I'd go for the 10 speed upgrade as it'll give you a better spread of gears, is lighter and more reliable than 8 speed and you can get spare parts easily should anything ever break.
Indexing, be it via downtube shifters or Ergo levers, is much more precise than friction shifters so just upgrading the levers would give a noticeable benefit.
If you want to upgrade further then the costs will mount as you'll need new hubs as a 10 speed cassette won't fit on an 8 speed hub. Campag hubs are either 8 speed compatible or 9/10/11 speed compatible as they changed the spline pattern in the move to 9 speed.
Personally I'd go for the 10 speed upgrade as it'll give you a better spread of gears, is lighter and more reliable than 8 speed and you can get spare parts easily should anything ever break.