Have you tested one of these out yet? Home machines that arent plumbed in tend to have shitty pressure which you need to get a decent espresso shot and to achieve half decent milk.
No Seylana. Your information is wrong..
Plumbing in a coffee machine just means you don't have to refill it.
Pressure comes down to the size of the boiler and heat exchangers and how much it can produce while active. High end equipment usually have either double boilers (1 for steam and hot water and 1 for espresso) or use a large tank with heat exchangers that allow both espresso and frothing of milk simultaneously without pressure being lost.
There are a bunch of other differences but that would require writing an essay.
Any coffee machine in the premium market are commercial grade equipment for home use.
Ultimately I want one of these;
But I don't have 12500$ spare to throw around.