No question which is the better - PS1.3, by a mile......... but, and it's a BIG 'BUT', there are SOME technical discrepancies, e.g. fuel system and autoflight. These are not major in terms of the total package but do not operate on the basis of "if it happens in PS 1.3, it will happen on the real aircraft" (It MAY do)
One further point to make, which comes from a few years as tech instructor on the 744 and others - while a GENERAL familiarity with your intended aircraft type prior to your training course is useful, getting too deeply into the systems on a self-taught basis is, more often than not, counter-productive. 'Un-learning' something which has been misunderstood is much more difficult than learning from scratch.
