Personally I dont think aluminium is a big problem but I might be in the minority. It is a good choice for a boiler with an external heating element becuase of its superior heat conduction. (most of the others probably have internal elements)
I dont know too much about the lelit but someone else will. it might be a better machine. baskets are 57mm instead of 58 like most machines, not sure if that matters.
I guess youve seen the second hand silvia on here for $500 but want to buy new for a present?
For the best coffee put a pid on one of these machines, but you can always do that later.
You could get the 2nd hand sylvia and a PID kit.