Any disadvantages to skid plates?

RCI is having a sale on skid plates right now (early April) and has me considering. I would also be adding the catalytic converter protection plate since cat theft seems to have finally made its way down to Florida. I do not intend to purposefully skid over any rocks with my truck so I will forgo steel and go with aluminum skid plates for more generalized protection.

Has anyone encountered any disadvantages to having skid plates on a truck? I'm aware of slightly more annoying oil changes...

Any disadvantages to skid plates?