The top of the Merit lineup. It doesn't reach near the bottom of other companies low-end.
If you have $600 to spend, put $200 with it and get the Horizon T101 made by the same factory. You will end up with a MUCH higher quality machine and you won't be wanting to do serious bodily harm to the store that sold you the Merit machine. It is just simply impossible to make a unit even approaching acceptable quality for $600. Those are just the facts of life with our current technology. Maybe in the future you can put on your Jetson's workout gear and to it for $19.99 but until then, a $1k treadmill is about the base quality level for most users.