Worth the money?

do they really make a big difference?

 

Daily driving probably not worth it in the grand scheme of things.... but you will get a cleaner signal and a balanced output.
I know in all my SPL builds a line driver is a must to fine tune!

 

well are there advantages from using a line driver versus the amps gain?

 

the amps gain is to match voltages with your deck

 

a line driver will put out a stronger and cleaner signal witch it will make any amp run more efficant. so thislets the amp produce more power with out the amp straining to pull more power to achevie its rated power. this also helps with low imp loads stains on a amp@ 1 ohm or low. over all a line driver is good in not just in spl but any application. when it comes to the meter u will see a diff with the line driver over with out one, by ear u wont know.