Comparing across eras is always difficult due to a number of factors differing, conditions, equipment, etc. What is clear, at least to me as a South African supporter, is that AB is one of the best going around currently across all formats. AB would also make all batting line-ups currently, again across all formats.
If he continues at this rate and consistency and stays fit, he could become one of the greatest of all time and not just one the current best! For South Africa's sake, I hope he continues firing in this WC and repair some of the heartache us supporters have always suffered in WC since readmission.