I have put Exide batteries into service with excellent electrolyte and it performed great - but the problem usually came out that the batteries were never similar - and I had to test their CCA myself - which had a variation within the same models.
Such batteries performed well with good upkeep in general purpose cars. The batteries suffered in extreme temperatures of -10C. The Hankook lead calcium batteries are similar to your lead antimony ones but have one odd requirement of higher gassing voltage of nearly 15V, they provide good service in Pakistan as all their products give similar and consistent result when tested.
They also work very nice in high load requirements like MB, BMW etc. vehicles which require 1000CCA with at least 100Ah rating with european sized batteries or sometimes AGM type - which exide Pakistan or any other local manufacturer fails to provide.
Price alone is not the dictator of sales, e.g. you cannot expect a lower priced part with lower spec and unaccounted data and no standard practice to compete against a specced price with higher price if the performance of the part is tested under great stress and cause money due to decommissioning the system.
In the above case the higher priced part will sell because it carries tested values and the manufacturer can be held accountable/questionable for loss of performance.
