I would never have a manual awning.
Over Labor Day weekend, at the Indiana State Park we were at, a bad storm came through on Saturday evening. Wind gusts were 60+ MPH and were enough to shake our trailer. They were strong enough to rotate a popup in the campground and bend the stabilizer jacks it had. Strong enough to topple a tree onto a trailer's slide, completely crushing it.
Low and behold, there was a family across the road who had a manual awning out when the winds started kicking up. The wife and daughters were the only ones at the site at the time (the husband was gone) and did not know how to put it up. I ran over and helped them get it up before the wind tore everything to shreds. An electric awning could have been closed by the six-year-old. Yes, it would have been nice if the wife had known how to close it, but she didn't.
We can pitch our awning any way we need to so water can run off. If it gets bad, as it did Saturday, we can retract it in about five seconds.
Basically, anything that makes my camping life easier and my setup/tear down time shorter, I want. Give me power.