Even though I'm very happy with the paddles I've got, I've never tried a stick--I mean a GP (sorry about that), but one of these days, I've got to try one for the heck of it.
I guess it all depends on what works best for the individual paddler when it comes to feather. I generally keep my blades aligned, except when paddling into a stiff wind. I haven't settled on a certain degree of feather--I just use whatever feels right at the time.
I had an old time ww kayaker tell me that I should be using at least a 45 degree feather all the time and more when going to windward. I said that I had tried that and it wore me out and it nearly caused a lot of near capsizes, due to wrong blade angle hitting the water.
The old paddler then said that whatever works for you is the right thing to do. I agree. The odd thing is that in one of my boats a 30 degree feather works better.