I have four Campy Chorus 2010-2015 bikes, a 2015 shimaNO 105 bike and a 2016 shimano Ultegra bike. 5 bikes are 39 X 53 and 11-25. The Ultegra bike is 39 X 53 and 11-28, although I very, very rarely use the 28.
I have found no difference in setup, in staying in-adjustment or noise levels. They all shift equally well with some slight differences.
The Campy shifts with higher finger pressure required, but more positively. Campy is faster on upshifts at the rear. Campy offers more shifts at one push of the button or swing of the lever than shimaNO. shimaNO is definitely slower in dropping to the small ring up front. Much slower.
My 105 brakes are noticeably more solid and firm than my Ultegra brakes and both are more solid than my Chorus brakes. The Chorus set will stop me as fast as the shimaNO ones despite the 'feel' difference. Tire adhesion being the limiting factor.
I use Campy Record Pro Fit pedals on the Campy bikes and shimaNO Ultegra SPD-SL redals on the shimaNO bikes. Other than the cheap sounding release noise from the shimaNO pedals, they are just as secure, solid, adjustable for release tension and comfortable as the Campagnolo models at 1/3 the cost.
Both brands of cranksets run equally well with Campagnolo being a bit smoother running and obviously much better looking. Noise levels are about the same.
Cassettes are a dead even match. Both brands are quiet and quick to shift. shimano's shift speed is limited only by their weird shift levers with the built in dwell time.
The 105 stuff is made in Japan. At least some of the Ultegra components come from Taiwan. All of it is good quality IMO.
One of my Campy groups has close to 30,000 miles on it and it operates just as good as when new...shifters included...with the usual replacements of a 53 ring, a bunch of chains and cassettes and one set of shift cables. Brake blocks are still OEM and hanging in there.
Will I get the same service life out of the shimaNO stuff? I don't really care. It's throw away priced stuff and I'm not concerned if it lasts or goes tits up. Replacement components are dirt cheap.
I know a guy that raced hard on his Token Chinese stuff for about five years and he swears it's great quality gear. Pretty much SRAM and FSA and all the rest have stepped their game up. Is Campy EPS still top dog? I couldn't say, but I would certainly not be afraid to bolt it onto any of my daily drivers.