I actually like the Guardian's Draw curve the best out of the bows you have mentioned. Smooth mods will make the draw much smoother and flatten the hump on models where they are available, but you will lose 7 to 8 fps. Within reason the draw curve is the last thing I worry about when choosing a bow and as long as you are not over-bowed your muscles become accustomed to it quickly and it soon feels like second nature. Ask yourself exactly what you are looking for in a bow.
Noise level?
Hand Shock?
Speed?
Forgivness?
Weight?
A to A length?
Decide which are the most important to you and choose the model that seems to best fill the bill for you.

Don't worry about what your buddy or anyone else shoots. Pick the model that has the Traits You are looking for

Dan