Sorry, I can't particularly help in resolving the matter... But I can say that I have the rancillio Silvia paired with a mazzer mini and my coffees are ahead of a lot of local cafés. I can't see any benefit from upgrading to a $3k+ machine apart from having the benefit of a double boiler and speed.
Have you descaled your machine in those 2 years? Do you back flush and clean the machine often? Also is the grinder often cleaned out from the old grinds?