For laptop pros: often have exceptionally complete ACPI support allowing sleep, suspend, hibernate, battery/ac power monitoring, device activity, thermal monitoring, cpu throttling, device wake up, etc.
For laptop cons: sometimes have exotic/proprietary devices/drivers.
Also, I think docking stations help with the easily removed pro. I can take the laptop in, and leave everything hooked up and undisturbed in the vehicle with a port replicator/docking station.
For desktop cons: often more heat (although my laptop get's plenty hot too)
Actually, I think it's hard to make generalizations on many of these things. All can be overcome for either given time and money. I am assuming that more time/money equals con?