Judging by your name I would guess you have some what of a bias opinion when it comes to Eastern punctuality, a bit like me with Flybe.
Flybe do not use BHX as a 'junk service' however if another aircraft has any problems they will look at sourcing the best alternative. This will include looking into a variety of things and it is unfortunate that the BHXIOM service has been affected in the past. Comparing EZE to BE is a difficult one as BE are far far bigger than Eastern and will inevitably suffer from more disruption as their network is so much larger.
That said, whilst I do not hold much of an opinion on EZE, it cannot be ignored that they are very punctual most of the time (not all of the time) and indeed have been acknowledged for this at airports within its network.
