Why Ti?
EFFICIENCY
Titanium is half the weight of steel, so titanium tubing can be made with slightly larger diameters without a weight penalty. Larger diameter tubing provides greater stiffness to efficiently transfer power to the rear wheel without undue flex, all without beating you up over the course of a long ride. It's a perfect combination of efficiency and compliance.
COMFORT
Titanium has enough strength and fatigue resistance to avoid very oversized tubes, providing a compliant, resilient ride on rough surfaces that smooths out and absorbs road buzz and small bumps alike. Steel frames, with their smaller tubes, can be almost as compliant, but aren't quite as comfortable. Steel may be real, but titanium is magical.
DURABILITY
Titanium is even more corrosion resistant than stainless steel. Internal cable routing is simple because the insides of the tubes are naturally impervious to rust and corrosion. Titanium can also flex three times further than aluminum and twice as far as steel without permanent damage. A titanium frame can literally last the rest of your life, and longer.