Yo, jmatt,
I had 3 Krupps steam toys over the first decade or so of my
espresso making experience and they
can produce an espresso-like substance.
I use the back side of a Cimballi plastic tamper for tamping the grounds.
The machine was "hot wired" several years ago (~20) so that it is always ON whenever the cord is plugged in. This allows me to wait until it is about to explode (well, OK, it will never explode since the boiler cap is a pressure release) BEFORE I switch it to brew...thereby providing more than enough pressure for a 2 oz. double.
She also has ample pressure for frothing milk and I have NEVER experienced the "super foaming" you mention. She does, however, steam like a "banshee" producing a pretty good micro-foam.
I think these steam toys fall somewhere between the (ubiguitous, in Italy) moka pot and a real espresso machine.
Oh, BTW, the steam toy is what we sometimes use for camping.
For camping it is either the Krupps steam toy - OR - the Gaggia Espresso.
Len