I use both. I find people who are completly against bits just as painful to tolerate as the people wh are complelty against NH or bit less.
I have trained horses to an advanced level in dressage and I break in wild horses so feel I have a fairly good and well rounded experiance to draw upon.
There are problems and advantages to both, but really training in either transfer well. I can have my horse work in a collected frame just as easily in a bit as a halter, if anything I find the halter harsher.
It's not the tool it's how you use it.