They are all HLHB with speed of 120. And if you look at their current arrival/departure history, you will find they are getting late regularly. The reason is overtakes of these 'durontos' by 130 MPS 'superfasts', due to MPS difference which is a reason DRM NCR has been giving for years.
Considering that Duronto passengers are paying surge pricing, these trains should immediately get LHB and upgraded to 130 so that passengers get value of what they are paying.
And this MPS upgradation is not possible with current hybrid LHB.