I agree. I'm a THF45 on Garuda (one of the most expensive servers if not THE most expensive) and I use synthing in the field to compress inventory slots for longer trips. I'm used to posting stuff on the AH in jueno for no less than 12k a stack, then send stuff to mules that sells for 4-10k a stack. Anything less than about 2k/stack to me is a waste of space and if not autodropped on location is sold to NPCs.

You are correct. With Desynths an exceptional result increases the return of the item.
Since Ex results are broken down into 3 tiers and 2 types, they can be identified by the step inwhich they are on the ladder as to the amount of stat increase or quantity increase that they provide.
Please note: most items only have a teir 1 exceptional result.

the two primary Ex results are Quality, and Quantity. Quality is the one that everyone is familiar with and everyone understands. Quantity is more confusing because most ppl don't actually pay attention to it.
Now when doing a desynth pay attention to your normal result. You should find that (such as this item) there is a constant amount you get (3). However, if you get a Teir 1 result, in the case of this (and most items) the quantity increases (goes to 6 in our example). Each increase is different by each item. Examples of items that have Teir 3 Ex results would be Potions and Hi-Potions. Though the results are not outstanding, they do give you an idea of how it works. Now getting Ex results from your crafting is another story all together, but just to add more fuel to the fire, not it is not completely random, there is infact a strategy to it. So go find it if you can:)

Please note: at this time Allakhazam does not appear to display Ex results for items that increase in quantity. My guess is that is because ppl are just stumbling into them in the common place. We should see more listings for this in the future for different items (I have sent in a request to update the page to reflect the Ex result).