The vocals to me is the hardest part to copy (or to do anyway), not only in tribute bands, but in any band. You can copy the guitar sound almost exactly, you can get the right amplifier, instruments, cables, clothes etc, but it all doesn't make any sense if you're telling
no story or have nothing to say. Check out this Jimmy Fallon tribute and tell me if this is the best thing or not! Imagine a DS tribute of this magnitude