Obviously the disadvantages are undercarriage scraping and ride comfort. But if you go too low, you might have problems with the wheel camber settings, that will tend to be negative.
That can that be fixed with aftermarket pillow mounts or camber screws. Due to the nature of the lower arm that are parallel to the driving wheels, these parts will only be scratched if there is a hump between the wheels. I don't recall any problems with driveshafts.
The usual touch point will be:
-The front bumper itself especially on parking lots ramps.
- Down pipe or center muffler that are positioned before and after the front wheel respectively.
-Wheel arcs/well to tires.
Stiffness and shock absorption of the suspension setup also determine what kind of problems u'll faced. For instance, I've made a lot more scraping here and there on stock JDM Levin suspension but not with another undisclosed aftermarket setup. Out of topic: Which brings up a question is it really okay for heavier four door SEG to be fixed with a two door coupe Levin setup? Because it's no good stock for stock.
If you are asking about problems that u may face when you lower the car by cutting out the springs or using miscellaneous springs, then maybe there'll be a lot more problems. Stock is always the best all-rounder.