We have been using a genesis bromine generator now for 5 months and we love it. The water is still crystal clear and feels great on the skin. We only have to add Ph down once in a while as the Ph tends to increase but that could also be due to the air jets. The bromine stays constant at 3 ppm and if we have extra people over we can crank the dial up for a few days. We also do not have to shock that often. Once every 2 weeks is more than enough.
As to the corrosion factor the sodium bromide is only approximately 2000 ppm so this is a very low salt content. We have non galvinized screws in our steps and I put non galvinized nails away from the tub as a reference. The salt water that has splashed onto the screws is not corroding any faster than the nails that are in the rain. Unless there is conclusive proof I an not worried about the corrosion factor. If you are worried spray down the area in the non winter months when you exit you tub.
Time will tell but we love the convenience and low maintainance of this system. We bought a demo tub and the water was in it for one year. If you can eliminate 2 water changes per year on average from other systems this will pay for new electrodes etc.