I like the convertible pants. I use them for everything from motorcycling to fishing and hiking.
I typically use compression shorts for undergarments and when combined with convertible pants everything dries quickly. So many times I can swim in them. They are also nice because sometimes I have to use a neoprene/velcro knee brace and I can easily get to it without having to disrobe.

It saves space and keeps me from losing things or forgetting them because I have to switch things from 1 set of pants pockets to another.

Most of mine are either Field & Stream or Columbia. Columbia tend to be more durable and heavier, while the Field & Stream are much lighter and less expensive.