Definetely noisier,sounds more like worn internals than like solid lifters, but as far as producing more vacuum and low end torque I can vouch for it. We put them on a overcammed 289 ford years ago and also advanced the cam a bit,
made it run a heck of a lot better than it did.
Of course the motor was built totally wrong overcarbed and overcammed with a stock torque converter. With the rhoads lifters it was considerably better (clickier too)