Titanium is light, and-if I understand right-very expensive in relation to steel. Of course, many of today's broadheads are simply incredibly expensive anyway! I am a professional sharpener and many of today's fine hair styling scissors are titanium coated. Based on sharpening those, I don't believe it is exceptionally hard, nor do the manufacturers make any specific hardness claim for it(like a Rockwell hardness rating.) Someone may correct me with a relative hardness here, but the stuff grinds away surprisingly easy with a simple honing process.
Personally, I would not be too interested in titanium as a broadhead material. Now, there are other materials that add resiliency, edge retention, and toughness to fine steels and those might actually mean more in the manufacturing of a broadhead. But, while they are common in high end scissor manufacturing, I have yet to hear of cobalt, molybdenum, tungsten, or vanadium being added to the steel used in broadheads. Not pretending that I know they would make a better broadhead, but they are alloyed in the finest steels for truly expensive scissors.