We've had manual awning on all of our previous 5th wheel's and loved them, because you could use the clamps on each side and attach to the metal frame. We would also put on side down, just in case it rained, which is what you should do so the rain will drain off. What made our campsite look great, was putting our lights out on the awning, which we really enjoyed doing everywhere we camped. Now with the electric awning my BC has, I have to put it in every night because it can't even handle a little wind or gusts. It is very handy just pushing a button to extend or retract but I personally would take the manual awning anytime over the electric, but that's just my opinion.
However, what I had heard 17 years ago when we first started RVing and always followed, was NEVER LEAVE YOUR AWNING OUT when you leave for any trip. You never know if the wind is going to pick up while you're gone and the wind can cause A LOT of damage, not only to the awning, but it can also destroy the side of your RV. I remember back in the mid 90's while staying at the KOA at West Yellowstone, MT we went away for the day to visit the park, and when we came back we saw several RV's where their awnings were blowing all over. Several were stretched to the point that they would have to be replaced. Also, I worked at a Nuclear Plant on the CA coast and everyday going to work, I'd pass people that had left their awnings out while playing on the beach and the same thing, awnings just blowing in the wind. I never could understand how people could do that but I think once you have that happen to you and you have to replace it, it probably won't happen again.
We use our camper every month of the year at the Myrtle beach. The electric Carefree awning can only be used in windy locations by the most careful of campers. We have to use tie down straps to prevent the awning from trying to violently close against the camper, plus attach to the camp site shelter and tie down to the ground. I did visit another camper from Quebec who added support posts under the outer rollup tube and tie to the ground. Until we or others come up with a better design /suggestion-we only fully extend the awning during calm or very light winds. Any time we leave the camper to go shopping, we bring the awning back to no more than 3ft (and have the tie down straps in the scissor section)or totally bring "IN" if there is the slightest risk of a storm approaching. 
