Large Bouncing Area vs Small
With the focus on lymphatic bouncing, the goal is to bounce just high enough to allow yourself to become airborne for a split second, and then decelerate. With a spring rebounder you can bounce without leaving the mat. With a Bungee rebounder, you have to jump high out of the mat to get enough g force to throw you back up again.
For rebounding doing the lymphatic health bounce, the sweet spot is really where most people jump in. The huge mat in my opinion is not necessary unless doing things like jumping jacks or wide leg squats.
When buying a rebounder that is designed for lymphatic purposes, unless you are super light weight, the larger mats do not allow enough G force with the feet barely coming up above the mat.
The Needak has the largest sweet spot. The Cellerciser has a slightly smaller sweet spot (it utilizes just enough coils unlike the Needak where all the coils are used for the same bounce).
The Lymphaciser, is firm nearly firm the way around. It is somewhat soft in the middle but gets real firm quickly as you stand near closer and closer to the frame.
The Reboundair feels more flat around the edges but sinks in towards the middle of the mat. It is mostly designed for the Health Bounce since they actually invented it.
The Urban rebounder has the smallest bounce area of all, but I not promote it as a lymphatic rebounder so it really isn;t part of my tests and doesn't apply to many of the topics on my site.
The Jumpsport has the smallest. Smaller than all the other spring rebounders on my site. Depending on someone's weight, and adjusting the bungee cords to its lowest yield, it is as close as you can get on a bungee rebounder to doing the Health bounce.
In a nut shell, the Cellerciser has the most even bounce but slightly smaller sweet spot than Needak. If getting an even bounce and doing the Health Bounce, the Cellerciser is my favorite for bouncing on the 28 inch mats and the Jumsport has the best bounce area for the Bungee type rebounders. I strongly urge people to get the smaller Jumpsport instead of their new 44 inch one. The bounce area is big if you want to use it like a trampoline but for doing the health bounce, forget it.