Yes, the weight of the blade affects its performance and feeling. However, people assume a heavier blade will be faster, which is not necessarily true.
Wood is not a homogeneous material, there are big variations in density within the same species, and generally speaking density is directly proportional to hardness and stiffness. So, you have two blades of the same model, one with 85g and another with 90g, where is the difference? This is the important question. You can even have two blades with 85g and significant differences. On a commercial blade the handles weight pretty much the same because they are made with fineline which is very consistent, so we can assume the difference is on the blade itself. Let's say they weigh 25g, that leaves 60g for the composition of one blade. The weight distribution within that composition can vary, you can have heavier outer plies and a light core, which will produce one result, and light outer plies with a heavy core, which will produce a different result. So, to answer my previous question, you can never be sure where the difference is. Generally, the core is the thickest layer in a blade, so it's probable that it becomes the main cause for variation, but this is not always the case.