As far as I know, Rossini is a HX. I was searching for info on La Spaziale machines groups 3 years ago short after I got my Vivaldi and there was a nice diagram on La Spaziale USA site, but now the old one is there no more and the new one somehow doesn't explain the LS HX as the old one did. (I quite don't understand what they suggest: link)
So 3 years ago it was straight that Rossini is a HX. Not to mention that the info about Vivaldi stated the brew boiler water is heated via steam boiler, which is of course not true. But the misteries with LS go further; in Poland the dealer does not comprehend what are the differences between Vivaldi and Vivaldi II... My guess is that I should get a job easily... no?