are adjustable track arms any good? what do they actually do?

 

depends on what you gone use them for, but take a talk to NUTS RuS on here

 

you've already got ajustable trackrod arms as standerd but if you mean the ajustable bottom arms i think you can ajust the camber angles which you cant normally do.
so basicly if your car is lowered, it would benifit from these to save your tyres and get better road grip ect.