The best yeast extract is undoubtedly the Essential own brand Organic, they also produce a non organic version I imagine as it is cheaper; I see no other retail reason. Essentials yeast extract is especially made from a unique production that is designed only to produce the extract.

With B12 Meridian yeast extract contains 3.5µg per 5g.

Meridian's main product is 12.6% salt. It says 5% Sodium on the label. Their other product has no added salt resulting in a content of 0.8% salt. The main advantage of meridian's products over Essential is that they have B12, something those who have poor absorption rates or reduced intake of B12 welcome.

If the base yeast extract was the same product, given the removal of 12.6% salt I would expect the [No Salt ]version's nutritional data to increase by 14.4%, clearly this is not the case.