Here are a few more items from my CaseLabs box. I got the 85mm top and the 64mm top, in addition to the standard top. Since I plan on this case lasting me through 10+ years of parts upgrades...I wanted to keep it as flexible as possible.
Right now, I've got radiators and fans on the top of the case that need to fit under the top....so I need the 85mm top. When I was selecting radiators, one of the requirements was for it to be less than 60mm, so that I could set it up this way. I like the idea if keeping the radiators compartmentalized and have hopes that it contributes to better air temps inside the main compartment of the case.
I guess the 64mm top would be for people who want the radiators on top of the case but won't be using any fans in pull. The standard top isn't deep enough to have fans on the top of the case...so its only for use when everything is in the main compartment. It would be nice if there was a top option of about 30mm that allowed just fans to be on top of the case. Maybe soon Jim?