In case anyone dig this old thread. I'm gonna answer my own question... now that I have some proper skills and both tops. QSH and Giulia are both amazing tops... BUT...
Off the box, with no customisation, the S8 is 10x better than the QSH. First big problem of my QSH was that it was imballence, so after converting it to fix tip and ballencing it to butter smooth that's problem number one fixed. Second problem is that the bearing that came with the QSH were old and broken. I don't remember when I first bought the top if
they were good but I have the feeling that I just had a dud. I changed them with some fresh bearings from Dale and with that and the proper balencing. now my QSH will spin for over 2.5 minute off a strong boomerang ( which is longer than my S8 ). So now. With that QSH vs the Guilia. how is one better than the other. The answer is they are different.
The Guilia is easier to launch airborne b/c of it's weight and is easier for tricking IMO b/c of the weight distribution. But on a nice trick sequence. the QSH will allow you do do more I think. But they are both amazing. So with the QSH I was able to pull consecutively 55+ crazy 8 while on the S8 I did 35 and then had to stop. The QSH handle itself less good at lowspeed b/c of the weight while the S8 can pretty much trick to the point where it doen't turn anymore...
Anyway, I hope is was useful to somebody