The Zen Pro 2 is the all time best selling linear machine I have sold out of all the linear brands I have sold under 3000 dollar. It has heavy duty steel fram and does not wobble or shake like the cheap ones. It starts out at 20 hertz and goes to 50 hertz. It can hold up to 300 lbs without bottoming out.
It weights about 128 lbs. About 38 lbs than the average one that weights about 90 lbs in its class.
It has different training programs which many people find helpful. This is very popular in chiropractic clinics as it was one of the first affordable linear machines. It has a 5 year frame warranty and 2 years on the motor. They also include 1 year of free labor.
The Zen Pro 2 is super quiet. It doesn't have that bog down sound even with people up to 300 lbs. (Their weight limit is not inflated).