Fortunately there are some
Check out this YT channel (link to videos about eTSI engines):
https://www.youtube.com/c/1001cars/search?query=etsi
They also do some other tests, like testing all assisting systems in the cars. Quite nice and informative.
Actually mHEV is what makes S&S finally usable. Generator-motors has enough power to start engine instantaneously without (much) vibration and lag, and additional Li-Ion battery used by this system minimizes the risk of battery failure.
My 2 previous cars were Seat Leon (1.4 TSI 122HP) and Ateca (1.5 TSI DSG). In both first thing i did was to disable S&S. Despite of that i had 2 battery failures in Leon within 4,5 years of ownership (one when the car was 1,5 year old). I did that to save engine, but also because engine start was annoying and generated quite some vibrations. And finally in Ateca it caused huge lag (not so much in Leon, as it was MT, so engine started when clutch was pressed, which gave more control over S&S).
Now in Octavia i never disable it. In a way stopped caring SO much about the engine, as i will probably change the car before anything happens anyway. But mostly because it's so usable finally. It starts engine in a blink of an eye, with no vibration and lag. It's perfect. And really saves fuel, especially in heavy traffic in the city.
1.4 TSI was exceptionally good engine. As said - i had Leon 5F with 1.4 122 HP (EA211). It was great. Very quiet, punchy and economical.
By comparison 1.5 is more noisy, probably due to GPF, and at least in the beginning it was not so economical (at least 150 HP version in my Ateca).
Now it's better than first series, but is it better than 1.4? I doubt it.
But i'm anyway pleased now. Just had a vacation road trip. 4300km from Poland, through Baltics, Finland, Sweden, Denmark, Germany and back to Poland. Mix of highways, speedways and smaller roads. Average speed around 100km/h. Average consumption from this was 5.45l/100km. Least i had was 4.7 in the Baltics (some highway in Lithuania, mostly one carriage roads), most was 5.7 (highways in Denmark, 130km/h, Germany, 130-150km/h and strong wind in the nose, and Poland 140km/h, next speedway in Poland, 120km/h) on 1100km trip. It's pretty good as for rather large car with petrol engine, with 2 adults, 2 kids and trunk full (literally full) of stuff for 2 week trip.
So far it seems Octavia is a bit more economical, than my Leon used to be (maybe by 0,5l/100km) and MUCH more economical than Ateca (roughly 30% - will never buy SUV again, unless normal cars are not available anymore ).