Very rigorous and very competitive than Microsoft or Google - (but lot more decent than Microsoft or Google); Very matured and experts in the field; If you interviewed or worked in Apple - you will notice the similarity with respect to what you can do rather than questions in Microsoft that tests what you do not know. Also interviewers in Microsoft are baby engineers asking coding questions with no human touch. You may expect a very subtle behavior questions and be very careful to not to answer what is not relevant.
Regardless of outcome, you will feel respected,