I dislike the lack of immediacy of shifting with bar ends. I think downtubes are faster and more accurate. Touring is often a loaded situation, and there are 2 camps to this belief
1- That you should never take your hands (either one) off the bars while balancing a touring bike, and for this the bar end shifters are better.
2- That you should have the best control over your gearing possible, and that favors downtube shifting.
I see and respect the rightness of either view. I currently have downtube shifting, both indexed and friction.