Just to clarify a few things Paolo said, to help his already excellent and improving English.
316L stainless is hard, really hard and to drill those extra holes smaller would never be possible. As a drill bit gets smaller, to drill into this material means 4 things. Very high speed (because of the small diameter), it gets really hot, affecting temper, pressure and coated bits. Under these conditions 1mm drill bit is very likely to break and I would imagine they break a fair number of bits making these. A 0.5 mm drill bit would not be realistic for this work. I know because I used to do machining work when I was younger.
Steel sheet, as Paolo says has a good and bad side. I have reviewed literally 80 machines and all of them inside have marks on the still as the bad side is hidden by the manufacturer. Cheaper machines using painted mild steel, will of course hide all this!
Izzo Alex Duetto MK1, photo when brand new
Quickmill Vetrano case inside. They have a factory building cases and have some of the best external finishes in the business.
Even with the best finish available, and their optically perfect looking external super mirror finish (in normal use)…look at certain light angles. Plus super mirror gets micro scratching super easy when cleaned. This was a new machine.
Rancilio Silvia in areas you don’t easily see!
My point is all these areas could be hand polished and cleaned up in Espresso machines. Very difficult time consuming and you would not want to pay what a machine like that would then cost.
