Which is a great machine? I really think that this question should be answered in two separate ways: great for location, and great for home use.
At home you usually keep a machine for several months, or ages, playing thousands of games. On location you play tens of games, or few hundreds at max.
So at home you can discover the deepest nuances of a machine, while on location you usually just learn the main elements of the game.
A game can have very catchy main elements, but lack long term playability over long time, or being repetitive. Usually hard and punishing games (if fair) are the ones who better perform long term in home use. This can depends from the deepness of the rules, but not only: also from simple playability itself in games with shallow rules (think early SS for example).
What you think?