In my experience, weight is less. The colas do get bigger. But after taking away the side branches the weight of two colas equal to about the weight of one full plant.(this of course depends on how many branches you have) So to get the same from one big bud, you would need to do two plants. So you dont save space, you dont get more bud, I dont understand the concept of the branch cuting. But yes it does make the main cola larger.
On a side note. It's harder to sell big buds. Unless you know people who like to buy by the gram (I dont). It sucks to have to cut a beautifull 20 gram bud in pieces cause you only need to sell a quarter or a half Oz, And you have NO smaller buds to make your bags weigh right. Just my opinion.