When it comes to the big lifts (bench, deadlift and squats), the Smith Machine is worthless in my opinion. When you do those lifts the "real" way, the bar doesn't move in a straight line like it does on a Smith Machine. And I stated in the other post, those lifts are all compound lifts meaning there are more than one muscle group being engaged and the Smith Machine certainly takes away from that. I can do a half assed squat with the Smith Machine, but I also have to lean back a little because the machine is also angled. Obviously putting yourself in an angled position isn't the safest.
The Smith Machine, however, is "safer." You're not going to drop anything onto yourself as there are safety hooks or latches or whatever word you'd like to use to describe them.
I really do like Hammer Strength equipment. I do very well with their incline bench and standard bench machines and I'm able to push myself really hard knowing I won't drop the weight onto my chest. Their row machines are terrific too. So I'm not anti-machine at all, but not a fan of Smith Machines.