The biggest choice is getting the right size mat. Many people want the larger mats although this gives a larger sweet spot to jump in it also cones in more and larger mats do not have the responsiveness that a small mat will give to do lymphatic bouncing. I only sell rebounders that have Permatron mats. The sporting good store brands have mats that feel like a potato sack. They usually off gas a horrible smell and their stitching frays quickly compared to cross stitched seatbelt material mats. The Cellerciser has the best threading (4 ply polyester). You can sweat on Permatron and it won’t ruin the mat. I avoid canvas mats. I avoid any mat over 28 inches in diameter to avoid pronation and inversion of the ankle. I have seen mats that have their hooks ripped through their mat since they weren’t stitched good. In order to get even mat tension, I always make sure the rebounder has springs that are equal weight. Some rebounders have springs with air bubbles in it making each spring a different tensile strength. Then the weak spring breaks first and you have to replace all the springs, not just that single spring to keep even tension. This is how they make money on you. They won’t say having a spring that was significantly lighter than the other springs was their fault and make you pay for a new set of springs.
Those with hip, back, or knee problems will want to avoid mats that give a high bounce. The smaller the mat the best it should be for these conditions. If buying a multi purpose rebounder, no matter how many times it was threaded, if it doesn’t have seared stitching, it can still having “running” of the threads over time. Those rebounders you see that have fuzzy all over the stitching is not the seared type.
For those that have balance problems, I urge people to avoid mats that are very firm around the edge of the mat and much softer in the middle. These will throw people off and this is when a balance bar is needed. If you buy the best quality mat you should not have to change the mat more than once during your lifetime use of the rebounder.