Is it worth the extra cost to go with an adjustable rear track bar or should I just go with a relocation bracket for my RC 2.5 lift w/ 3/4" spacers?

 

Its definitely worth it to have adjustable trackbars. You'll need them eventually anyway. A relocation bracket isn't a bad idea either if you get one that helps reinforce the weak stock bracket.

 

With my 3" lift, I added both the JKS adjustable tackbar and the JKS welded brace.
Was going to put on the Terafex bolt on brace, but welds on stock bracket broke
2 days before install. Have brand new TF brace for sale $40, paid $83.

 

Peace of mind is priceless! get the adjustable bar.

 

if you can afford it, an adjustable track bar is always the better way to go. certainly, it will allow you to recenter your axle perfectly. depending on the drop bracket you get and for how much lift it was designed for, you may find that your axle will still be shifted over a tad or in some cases, over corrects to the other side.