Question about Ssupd Meshlicious Full Mesh

Besides the versions with/without glass side panel, the main difference is the PCI version compatibility of the included PCI riser cable (PCI 3.0 or 4.0). The more expensive version has a PCI 4.0 riser cable, I recommend you choose this one. All reasonably new graphics cards use this standard and you are guaranteed the full performance of your graphics card. PCI 4.0 is of course also downward compatible with PCI 3.0 hardware. The case with PCI 3.0 cable is only recommended if you are planning to use older hardware and not an upgrade.