This is a little more generic than this thread, but it has to deal with game design in general, and communities who try and balance their games.
There has been a tendency to underpower game mechanics. This is because a group of people will dislike mechanic A, and so even though mechanic A is balanced, in thir minds any effective use of the item will be a sign of its "overpowered design." Therefore, these people often want to rebalance mechanic A so that it's effect on gameplay becomes negligible.
After enough whining, mechanic A is finally nerfed. For example, for a while in classic WC3, this was an incredible problem. Even though the races were statistically balanced at some points, people simply didn't like some of the tools being used. Hence, they complained until the items were finally nerfed, at which point, NOBODY USED THEM.
To tie this into the buckler, or any other T:V object, everything has to be SLIGHTLY overpowered. If it isn't, then it won't be useful enough to be taken. In other words, nerfing items is often the equivalent of removing the item altogether. If the buckler isn't marginally advantageous, then nobody will use it.
Therefore, you don't want to make something a DISADVANTAGE to hold. You want to make holding anything advantageous, in order to assure that those things are even used. In theory, this buckler seems to be balanced. I don't think it's overpowered until it overwhelms all other game mechanics to the exclusion of even using them.
