Even for the picky person this is the machine to get if you are not willing to splurge on the ubermaschines
Positive Product Points
-Shot quality is simply awesome _AND_ consistent, even through multiple successive shots -Steaming (using optional 4 hole tip) plentiful, and easy because of the pivoting steam wand -Volumetric dosing, one less variable to tweak!
Negative Product Points
-I would have preferred it would out of the box turn-on on power up. (vs go into standby) -It's a bit on the noisy side of things, too little was done to dampen vibrations -No thermal insulation of the boilers to reduce energy consumption -Build quality does not quite impress me
Detailed Commentary
Do not get me wrong here, I love this machine. I realize that my list of negative points is longer than the positive points. That is more because I'm really picky. I would buy this machine again in a heartbeat. (Unless I was willing to fork over the money to get a GS/3 or speedster).
Let me elaborate on my negative points, since the positive points speak for themselves.
Power-on: I have a X10 switched outlet for the viv to use that is controlled by a timer. This is not going to work unless you hack your S1 to switch itself to power on from standby mode (notes available).
Noise: Out of the box the whirring of the fan and the rattling of body panels creates quite a ruckus. If that bothers you, you can easily add a couple of rubber grommets and dampening materials to improve matters drastically.
Build quality/price: The frame is painted steal, with steam, temperature changes and vibration plentiful I'm worried about the machine showing the marks of oxidation in the not too distant future. Personally I feel espresso machine chassis should be made out of SS to prevent this. Also, my machine had the screws that keep the electronics box in place misaligned causing it to rattle loose. I fixed this myself. It is also my personal opinion that these machines are overpriced, if I look at the engineering complexity and the bill of materials of the device it is hard to justify its price. Having said that, I realize that the market is small and it is a luxury item. Similar machines (Think Vib. Double domo super automatic) are at the same price point and a GS/3 or speedster is a completely different order. Hence, these negative points should be taken into that context.
Buying Experience
Can't go wrong with Chris on this one. The Vivaldi II is his iteration of the S1, with must have extras