Sorry, guys, I know you invested a lot of effort in this, but it really is very expensive and stylish junk.
Positive Product Points
Looks great. Very complete instruction manual.
Negative Product Points
Has Gaggia guts, with attendant quality and functional problems. Despite dedicated steam boiler, will barely steam 4 oz. of milk at a time. Gauges are nearly useless.
Detailed Commentary
This machine has style, no question about it. The housings are well-made, from cast alloy of some sort.
Unfortunately, it appears to share its working parts with higher-end consumer Gaggias (see my review of the Gaggia Baby for my other problems with these). It was deja vu all over again, except that the overheating and charring problems I had experienced with the Gaggia did not appear to be as bad with the ProLine.
The gauges on this machine are for style only---they have so few graduations for temperature as to make them virtually pointless. Releasing steam from the boiler causes flash over, which pegs the steam gauge. The lights on most commercial machines are actually more useful than these gauges, because you can at least tell when the element(s) are on, without having to listen for the clacking of relays.
The biggest disappointment with this very expensive machine, however, was the steam boiler. If you're going to make a two boiler espresso machine, why put a dinky little steam boiler on it, that can’t handle 4 oz. of milk without a rest? I corresponded with Kitchenaid customer service about this; in spite of their apparent effort to consult some experts while putting this machine together ( the manual really is excellent), they never seem to have considered that anyone would want to steam more than 4 oz. of milk at a time! I'm not making this up----that was actually the gist of their response to my question!
I gave up after two weeks and took the machine back to W-S. That’s another story.
Buying Experience
I bought this from the Williams Sonoma at Baybrook Mall in Houston, Texas. I have never heard anything but praise for their customer service, including their essentially unconditional return policy. So I was frankly stunned when I had to return the machine, and was subjected to icy hostility and interrogation by the manager. She glared at me as if I had offered to feast on her children, and demanded a detailed account of my reasons for returning the machine. Haven't been back.