Can someone give me the run down of what exactly each mod will do.
Lowering Springs $199 (plus install) Heard these will only make my car ride like crap...why would anyone do this?
Coilovers $1475 (plus install) Cant seem to get a for sure answer for anyone as to what the upside these will bring.

Lowering springs will increase handling if u lower it 0.5-0.7 inches.
Any more lowering & it will ruin the handling.
The lower the car, the less comfortable, but u will not really notice the comfort difference.

CoilOvers r adjustable springs. You can lower & raise the car whenever u want by adjusting the springs.
This can also help with handling if u lower it about 0.5 an inch.
Lowering springs cannot be raised. You need to buy bigger springs to raise ur car.

lowering springs = lower ur car, increase handling, with the trd springs it puts less strain on the stock parts of the car (i.e. struts, shocks). it lowers ur car about 1.5 inches but after it settles & the shocks get worn in the car drops to about 1.7 inches. people get this because it is cheaper & increases handling. if u get a good brand of lowering springs (i.e. hotchkins, tien) they will feel just like the coilovers.

coilovers = adjustable height level, better for racing/tracking if you're planning to do that. but essentially they do the same thing as the lowering springs do which is increase handling performance, but no real major upside to these vs lowering kit.

think of it this way, if u adjust ur coilovers only once, u have the same thing as lowering springs, basically.

oh, & if u plan on lowering ur car past 2 inches it is recommended that u get a camber kit to help straighten out the wheels & prevent them from rubbing.

l think the look of the lowering springs are great. the Scion tC comes with plenty of play space for the tires. Although it may make for a more bumpy ride.