Do gear bonuses stack?

That is, for Vog Cup set they both offer "Attack Speed Increase: Medium" but does wearing both mean your attack speed is higher than wearing one? Do the two mediums combine to make a high or something.

Also with charge times, a level 10 bomb will have Charge Time Reduction: Medium, so does wearing the Mad Bomber suit reduce the charge time again as it also offers Charge Time Reduction: Medium.

Thanks for the help