There are too many variables in a question like this for anyone to be able to respond with a straight answer. I believe that the GS3 is probably the best 1G on the market, but not many people can spend $7500 on a single group machine.
Depends on what features you decide are "necessary."
Hard question to answer. It definitely depends on what you want to use it for. For a small volume coffee house, the GS3 would be a dream. If it was for like a cafe that maybe made espresso every so often, you might look at the Andrea Premium. But again, it all depends on what your setting or volume expectations are. Good luck!
Have you taken a look at the LaSpaziale S1, or the Vavaldi single? You might also want to take a look at the NEW Rancilio Lever units, all manual operation, way cool. We have a single in our show room (we have also sold 3 2 groups in a single month recently) and it is a dream to work on! Good luck.
I would reccomend a Baratza grinder (http://www.baratza.com/) instead of pre grinding. These are solid home grinders that can easily make the transition to a light commercial use decaf espresso grinder. You can get them from $150-450, but they i thi…