Is the rock guard worth putiing on a PD 36, I run mainly in mud but also plan to use in rocky trout streams. Does it increase drag and slow your boat?

I would recommend not using the rock guard. I have had my PD for 3 years now and only used the rock guard the first few times out. I run a very rocky part of the river and am still on my original prop...105 hours later. The amount of drag and performance loss is significant and the skeg does a very good job protecting the blade. I knocked the back end off that runs past the blade and it still does a great job. You may "side swipe" a rock or two but so far, the motor has taken it and the added performance allows you to get on step faster and run shallower minimizing the impacts. It really doesn't happen if you pay attention.

For me, I would rather have performance (and it does pull making it harder to turn and run the boat) and replace the blade every few years.

i would agree as far as the pd guard. way too big. i run a mb w/o a guard and the prop will hold up to gravel and even hard impacts. it doesnt look real good but the main profile of the prop hasent changed. lots of nicks ans gouges but no real prop wear. thhat being said my bro-in-law has a guard on his mb. its not near as big as the pd guard. it doesnt seem to effect the running and has kept the prop like new. if you put somthing like that on a pd ide think it would help, just not sure how the lower on the pd is made, or if it would tear out?