I <3<3<3 my Macs, but the laptops are not any more sturdy than Windows laptops. They are much less infested by viruses and malware, but that may change at any moment. If you feel comfortable with Windows and have applications and support system, there's no good reason to change. Unless you want to!

The netbook might be a good compromise, you have your full-featured laptop for serious work and the netbook for surfing.