Like many, I was a bit surprised at the price disparity between the Ming 17.01 and the 19.01; however, at the time the 19.01 was launched Ming Thein was careful to point out that it merely represented a different approach, not an abandonment of the 17.xx series and the accessibility it represents. The 17.03 GMT is just a hair thicker than the 17.01 (the 17.01 is 38mm x 9.3mm and the GMT is the same diameter, but 9.8mm thick). The case material is now Grade 2 rather than Grade 5 titanium (Grade 5 is a titanium alloy, with some vanadium and aluminum and Grade 2 is basically pure titanium) but it's still nitrogen filled, and the case construction remains the same in terms of machining the case interior so the movement fits exactly within it without a need for a spacer ring.