After doing a lot of research, I recently purchased the Needak non-folding rebounder based on the recommendations of several websites, the main two from bouncewell and needak-rebounders.
The Bouncewell website compares 4 models and then follows up with recommendations of each rebounder depending on what you are looking for.
The Needak website compares theirs against ReboundAIR which, of course, could be bias. However, in addition to testing the ReboundAIR, a lot of the information on ReboundAIR is based on statements found in ReboundAIR promotional materials, direct observation and sources deemed to be reliable.
My main goals were to buy direct from a manufacturer and not from marketing/promotional companies. Also I wanted easy access to parts for repairs. I chose Needak (in Nebraska) because it is made in the United States whereas ReboundAIR is made in Asian countries and I did not feel that availability of parts would be as good. Most rebounders are made in Asian countries.
A good article to read which was published in the "Townsend Letter to Doctors" and features the Needak Rebounder is 'Jumping for Health' by Dr.Morton Walker. He lists the Specifications for the Perfect Rebounder at the end of his article. See the notdoctors website.
Another research article on Aerobic Resistive Rebounding with weights, is by Dr. Harry Snelder. The step by step logic is mind-boggling! see the urbanrebounding web site.