I finished up filling the cracks in my concrete floor and once that material cures, hope to get some rubber flooring in place. I'm looking at a ¼ inch product. I will need to be able to roll items like my bandsaw, drum sander, clamp cart, etc across the floor so I'm not sure if I'll regret not going up to 8mm or 3/8 inch thick. Trying to keep the cost from being too high, but also to having something that is workable (i.e., more expensive to have to replace!). I do have rubber flooring in a workout room that I think is 8mm and it is more than sturdy enough. 

Interested if anyone has used similar flooring in their shop or has other input on recommendations or regrets.

I have mats all over the place at every workstation and then some. All salvage from drug stores. I do believe you could get by with the 1/4 and use mats at workstations. Horsestall mats are good from what I have heard. I also salvaged some rubber floor tiles from a Walgreen. Think it is about 3/4 thick but it ain't cheap. Goes together like a puzzle.