Euan,
you have in fact two different kits, the Esci one and the Dragon copies (Zvezda, Revell ...).
Esci one is reputedly better because of correct troop compartment roof hatches position. Some other details are better too.
But like on the Dragon "family" the sprockets are wrong and the turret will need some extra work to get an accurate model.
The Dragon "family" has the wrong angle for the troop compartment roof hatches. This is not an easy fix but you have some alternatives, SP Designs being one.
The turret requires a good amount of job too.
The Afghan variant is simplified (both on Dragon and Zvezda re-issue), the add-on armor plates are partially wrong.
If you are interested you can see my own BMP-2D (or E according Dragon) here at Armorama.
my BMP
Enjoy your build!
Olivier