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If money was no object the espresso machine I would get would be the La Marzocco GS3. Although it came out several years ago, it still is pretty much the state of the art espresso machine for the home setting (of course there are other machines that just came out that has new thing such as pressure profiling, but for practical purpose, those machines are for cafes).
The GS3 is actually sold by roaste: http://www.roaste.com/product/ChrisCoffee/La-Marzocco-GS3-Espresso-Machine
The GS3 is a double boiler espesso machine but unlike previous incarnation of double boilers, it is even more temperature stable due to improved plumbing. Although I never had a chance to see the GS3 in person, I can only imagine from what I read and see of various video as well as my experience with refurbishing the Marzocco Linea. A major weakness of most Linea is that during the brewing process, the cold water would enter the brew boiler, lowering the overall temperature (not by much but it is significant if the initial flush volume is high). Additionally, with the older generation of Linea Automatic machines, the flowmeter and the solenoids can drop the temprature of the brewing water thus also affecting temprature stability. The GS3 improve both of these issues by having a heat-exchanger running through the steam boiler to pre-heat the water that is destine for the brew boiler, thus eliminating any potential drastic change in brew boiler temprature. Additionally, the solenoid is build into the group head thus eliminating any drop in temparature as water pass through it. Furthermore, the flow-meter is located up-steam of the brewing water and only cold water run through it so it does not drop the brew temprature. Top this off with an uber precise PID, full stainless boiler and group heads and you have a dream machine for any serious enthusiast.
However, the price of the GS3 is astronomical, it is among the most expensive home espresso machine (perhaps with the exception of the speedster) thus it will just remain in my dream for a long time