One thing that used to bug the hell out of me was the fact that D&D used to measure how much you could carry in coins. Not only that, the equipment list didn't even list things in kilos, only coins! I thought it was unrealistic and focused the game only on grabbing money, which I thought was a baser form of enticement for adventuring. Pretentiousness in its base form, really.
Now I've realized that this is a design feature. The fact that you get experience for gold, actually emphasize the fact that you're better of fooling monsters out of their treasure than slaughtering them.
In the Swedish RPG Drakar & Demoner [Dragons & Demons, original, eh?] which I grew up playing, the curious invention of Encumbrance points saw the light of day. They were supposed to include not only the weight, but also the volume of things. Naturally, some of these numbers felt seriously wonky.
So, when I started my present campaign I decided to toss all kinds of encumbrance. In T&T there are something called weight units which one tenth of a pound. Why on earth invent a new unit if it's just a bunch of kilos/pounds with a new name?
What kind of campaign will benefit from encumbrance rules? I've been thinking about that a bit, and realized that the only kind of game that I intuitively feel would benefit from it is a post-apocalyptic one. In such a game where resources are scarce and where barter for high tech might be reasons for adventuring, I can fully see the need for a system that keeps track of stuff. Traditionally games about plunder, i.e. classic dungeon crawls, seem to be candidates for that, but now I'm not so sure.
In my last 3rd edition campaign (which I'll probably write more about at a later date) I once put in a pile of loot, with the idea that encumbrance would stop them from hauling it all home. Since there was a table in the DMG that told me what amount of treasure a party of a specific level "should have", the game suddenly ground to a halt when one of my players was inventive enough to figure out a way to haul it all home! Now what I do? Let them have it, or curb the invention? The mother of this dilemma of course the idea that I did the stupid thing of showing them all the stuff they couldn't have, and teasing them. That is not only cruel, it's bad manners and bad game mastering. Let's just silently sidestep the crazy idea that there are a level of treasure a PC "should have", and focus on good game mastering.
Good game mastering is about facilitating fun, and letting the players do what they want to test their wits and stretch the resources of their virtual personas. Counting on rules for encumbrance to limit the players is just laziness. Give the players meaningful challenges and they will surprise you with their inventiveness. It will be fun! In my game now, we all ignore weight and how much the characters can haul about. Will it break the design feature that it was intended to support? No, I don't think so. I have begun to like the idea of giving experience for gold, but since I'm not using that rule I think the best thing you can do about those "weight" entries in the equipment lists is to toss them out. If someone finds a dragon hoard and defeats a dragon, then they probably deserve to bring it back to town. No matter how unrealistic it is.