I´ve been riding both BMP-1 and CV-90, guess which was more comfortable and offered more "personal space" for the poor grunts with their rifles, a PKM, 4 LAWs, and an occasional APILAS, maybe a few Anti-Tank mines also.
It is difficult to stuff 7 soldiers with their webgear and weapons in a BMP-1. Keep your helmets on, a true cross country joyride, with different protruding metallic objects poking everywhere.
BTW squad leader is usually the APC-vehicle leader, and usually the driver is also used in defending positions as a regular infantryman, if he is not vital driving his vehicle around, as in advance and assault-type missions. However in IFVs the situation is different as the vehicle is considered combat-capable.