Actually, in my case, I consider a pee valve a safety item.
Some time back I took an "undeserved" hit, and the hyberbaric doc said that one of the major contributing factors was being dehydrated. Now I have a pee valve and hydrate up like crazy and life is good.
You know, this is why I took to using the system. I found that I was trying to limit intake for all of the obvious reasons. Now I hydrate much better.
But the comment about other issues is real. You have more personal care to consider and it involves another pre/post dive step to not miss or mess up.
But then again, no such thing as a free lunch, is there?