-Fine tuning of dose
-Fine tuning of temperature
-Deep 53mm portafilters
-Produces incredible steam
-Produces great shots consistently and is very forgiving

-Can’t be used on a timer
-Tough to remove baskets from portafilter.
-Driping expansion valve

I currently own an Isomac Tea which I purchased from Chris based on the outstanding feedback provided by this web site.  After a year of using the machine, I decided I wanted a machine in my office as well as home so a second machine was needed.  The counters in my home are granite which originally eliminated the possibility of a plumbed in machine.  Considering the excellent experience I had with Chris (and Mary) with the first machine, I decided to consider the Andrea.  The more research I did, the more I decided I really wanted a rotary pump machine.  The programming features of the S1 also appealed to me.  After evaluating my kitchen situation again, I decided I could give up a soap dispenser which is built into a second sink I have and run the plumbing hose up through the opening vacated by the soap dispenser.  Before taking the plunge and after numerous hours of research on this web site, I decided to call and talk to Chris which is worthy of comment.  I called an asked to speak with Chris indicating I was a previous costumer and really want to get his feedback.  He was on the phone speaking with someone else but called me back in less than 10 minutes.  I explained where I was at and he literally took over 20 minutes to discuss the pro and cons of each machine.  At no time did he ever try to get me off the phone or seem inconvenienced.  He also informed me of Chas’s forum and Dan’s article (both of which I had perused).  It re-enforced my comfort in purchasing the S1 as well as Chris’s commitment to customer service.  I purchased the machine the next day along with the softener and filtration kit, it arrived in less than 4 days.

Installation.  The toughest part was installing the filter system under the sink because of the garbage disposal.  It was virtually impossible to get a drill underneath the sink to mount the filter brackets.  Otherwise the job was relatively straight forward taking about an hour.  I would highly recommend that a pressure regulator also be installed.  My internal house pressure is about 60 PSI vs. the 20-25 PSI that most people seem to recommend for the machine.  The increased pressure has been the subject of much debate and the potential for leakage.  My conclusion is that 60 PSI is great when you take a shower, however, your espresso machine will probably feel otherwise.

Operation. Configuring the machine was a breeze.  The machine came preset to 95 degrees centigrade which is almost exactly 203 Fahrenheit.  Very close to what Schomer recommends for ideal extraction.  If you want to change it, the procedure is very straight forward and easy to do using the buttons on the front panel.  Pressure is preset to around 9 bar.  Setting the water dosage is quite straight forward as well.  The machine is put into configuration mode by holding the power button for 3 seconds once it has already been  powered up.  The first time a shot is pulled, the machine will remember the amount of water which is used when the shot button is hit the second time to turn it off.  From this point forward, that will be the prescribed dosage.  I programmed the single shot button for a very long pour so I could use it to flush the group head of grounds after a shot.  I programmed the double shot for a 1 ounce ristretto.  

I noticed a couple of things immediately.  First, I needed a coarser grind to get my 1 ounce pull in 25 seconds vs. the Tea.  I suspect the filter design and pressure have something to do with this.  The Tea is set to around 9.5 bar and uses a shallow 58mm filter basket.  The S1 is set to 9 bar and uses a deeper 53 mm basket.  I have found the deeper basket is significantly less prone to channeling.  I have also found that the S1 is much more forgiving if the shot takes longer to reach an ounce.  Please note I never use the single basket in either machine.  All references are to a double 14 gram basket.  

Cleaning is also considerably easier.  A nut is used to fasten the group head screens into the head.  On the Tea, the gasket is used to hold the screen in the E61 group head and is rather challenging to remove.  On the S1 removing the screens and diffusion disc is as simple as loosening the nut until they drop out of the head.  They can be rinsed and cleaned easily this way.

I only have a couple of minor issues with the machine.  First, removing the baskets from the portafilter requires Herculean strength or a screwdriver.  If you choose the former, you will do it at the risk of your finger nails.  Second, the machine is completely processor controlled so it can not be placed on a timer.  The machine requires the press of the “On” button which appears to be a solenoid, before it will actually engage the heating elements in the two boilers.

All in all, I love this machine.  The ease of use and configurability are outstanding as is the espresso it produces.

What can I say.  This was my second machine from Chris and my second Mazzer Mini.  I wouldn't buy from anyone else.