I bought my S1 VII brand new, and I got rid of it after about a year. I felt for the price, it was way too troublesome.
I had several things go wrong with it more or less from the first month to the last month. As I recall, metal shavings in the unit in 3 places I had to find over time, bad rotary pump, bad 3-way valve, bad flow regulator.
Chris' Coffee was awesome, and sent me all the parts and helped me in troubleshooting. The S1 forums are also awesome.
Honestly, the worst parts was not being able to find any decent 53mm tampers or triple baskets, and the factory drain kit was awful; I had to modify mine to work. Also be prepared to break out your metric wrench sets. I think it takes everything from 3mm to 27mm
I am back to a Livia90 I got for a great deal, and while not as fancy, it has been pretty easy and cheap to work on, and really has not needed any maintenance once I got it up and running.
Chris