slightly off topic, but if you want to get lower and your hamsting flexibility is an issue, then try sliding your saddle as far forward on the rails or a 'fast forward' triathlon seatpost which has now setback (you might even get way with rotating your current one if the angle adjustment allows, then you effectively can rotate your body down, while retaining the hip angle that gives you good power. You can also sit right on the nose of the saddle.