When I was at the SEMA show before the last one I saw a set of JBA Taco headers.
I was very disapointed in what I saw. They appeared to be of low quality, mild steel, sloppy welds, lots of spatter inside the pipe and so on. Remember this was a show set and you would think they would be more then perfect if they were going to show them off.
Lets face it, the TRD headers are gorgeous. The welds are very nice, the pipes are clean inside and out. They are stainless and appeared to be very well engineered.
Now when the TRD headers came out there were some problems, serious problems like a very poor gasket designe that was very prone to leaks and bolts that would come loose. At first they addressed this in typical Toyota/TRD fasion, deny there is a problem, blame the installer and so on.
Later they finally fixed the things that were wrong with the headers and I really believe that they are a very nice set and should be your first choice. Of course they are not cheap, but if you were looking for cheap, then you could of gotten a Ford Ranger, right?
I have never seen any dyno charts comparing JBA to TRD headers so who know how they compare there.