Can't answer as to laptops specifically. However, I asked a friend just the other day what she thought about her new smart phone. If I had been asking about smart phones in general, I think I would have asked what she thought of smart phones. The "of" in that case indicating more of a category question as opposed to a specific question regarding her smart phone where I used "about". Hadn't even realized I was making that kind of a differentiation until I saw your question.