However, you would need less than an hour to convince yourself that the Mazzer Mini is nowhere in the same league as the Robur, for example, speaking strictly in terms of the added demand on technique. That is the real secret behind the WDT - it compensates very nicely for grinder shortcomings. I don't have a firm opinion on the flat burr versus conical burr difference, though my brief tour with the Versalab M3 and weekly experience with Mazzer Roburs certainly supports claims by knowledgeable home baristas that the conicals are behind much of the improvement.
Currently I'm informally evaluating the La Marzocco GS3. Counter Culture has welcomed locals into their espresso lab for the past couple years, so I'm fairly familiar with LMs (e.g., Linea 3AV, FB70, and GB5). While upgrading to commercial machines generally reduces the demands on the barista, the opposite is true sometimes, as I've found for the lower "forgiveness factor" of the aforementioned LMs. That said, it's only day two and it's clearly evident the GS3 is in another class compared to its brothers. Whether that incremental improvement in forgiveness (which may be little more than a smaller gicleur and start/stop preinfusion, I honestly don't know) is worth the cost of three semi-commercial E61 rotary espresso machines is a debate between you and your wallet. For the majority, I agree with Chris' recommendations: Spend your money and time elsewhere.
Like the audiophiles' world, the cost increases non-linearly relative to the benefit. The good news is the top end stops much sooner for espresso gear. While you could drop $10K on espresso equipment for your home, few would see any appreciable benefit at less than one-quarter that amount because they are gated by their own skills (The problem is on the handle side of the portafilter is my mini-diatribe on the subject). According to some hardcore audiophiles I know, that same amount would be a nice down-payment on speaker cables.





