jz4analytics
Maybe someone can confirm, but I was underived the impression that the algorithm does NOT weight scores in any fashion whatsoever. A point is a point, whether that be a Q50 over a Q49 or a V40 over a V39. GMAC has said in the past that it is not weighted, and you can check the old paper test grading (assuming that the Total scores isn't calculated differently.
Scores
are "weighted" on the GMAT. Every test is designed around certain objectives, and the GMAT is no exception. The GMAT does not want or need to reward extreme scores. For example, getting a 51 on verbal won't help you any more than a 46 (or so) will if your quant doesn't go up from 50 as well (

). Each "point" that we get on the GMAT is a measure of ability and the relative rarity of that ability "level"
does change over time. It hasn't changed much for verbal, but just look at what's happened in quant. The percentiles have crashed (a lot of the ability "levels" have become much more common).
jz4analytics
Also, I believe we get different Total scores from the same Q+V scores because the underlying section scores are not integers. So the algorithm might convert a Q47.4+V38.4 to a 700 but a Q46.5+V37.5 to a 690 even though both will show Q47 V38.
The underlying scores are integers. It's just that that underlying scoring scale is different from the "51" scale and is more accurate.