There are a few things to consider when considering a plastic flooring tile. Especially when cross-shopping a slotted tile versus a solid tile. The main things to think about here are functionality and aesthetics.
Functionality:
Swisstrax Ribtrax PRO or Smooth PRO have a slotted structure that allows dirt, debris, and liquids to fall through the small cracks in the tile. This means that the tile acts as a filter and keeps these things out from under your feet and not being tracked around your garage. Think of how a Grit Guard works in a wash bucket: it keeps the dirt from floating back up above the Grit Guard, keeping the water above clean and keeping you from putting your wash mitt on the dirty bottom of the bucket. Swisstrax Ribtrax works in a similar fashion for your floor.
You may think that this would be a nightmare to deal with, getting all that gunk and stuff under your tiles. But in reality, it's very easy to vacuum regularly or unsnap sections of your floor and pull out into the driveway. You can clean and vacuum the entire space and have your floor back together in half an hour or less. This is really only needed once or twice a year. Water also flows freely under the tiles due to the channels underneath.
Diamondtrax or other solid tiles lose out on these features since they don't let debris and water through. You end up with the same debris and liquids collecting on top of the tiles, or getting stuck in the edges between the tiles.
Aesthetics:
Diamondtrax has a cheap, tacky look that we don't prefer at Obsessed Garage. Standard Ribtrax PRO or Smooth PRO look and feel amazing. We will always choose a slotted tile over solid.