Are Motorised Retractable Awnings Better Than Manual Retractable Awnings?

These types of awnings have been used on RV's for decades. I don't have one on my house, but the same issues probably apply. They do not tolerate high winds, they don't shed rainwater efficiently, require constant upkeep and cleaning for dirt and mildew. Whether it's motorized or not depends on your price point.

I would go for simplicity, practicality and fitness for purpose.
Just making the property look pretty does not to me constitute a valid purpose.
Shading the terrace and making life more comfortable does.
Reliability is proportional to number of moving parts.
A row of hooks, a couple of poles and some guy ropes would probably do the job and also be more flexible in terms of size and shape of shaded area. If it was made with good quality materials it would look like a 'designer' feature. It would also be easy to take down clean and store for the winter. Prably cheaper than a commercial unit too.
If you make one, be sure to post it as I could do with one across the back of chez cat
Del

Motorized or manual more beautiful? Neither basically they are the same.

No no no no no, a pretty lady in a bikini helping you put up the awning on the first scorching hot day. Gotta be more beautiful... besides, the exercise will help keep you both trim rather than pressing a button, wondering why it doesn't function after 6 months without use and then slumping back into a sweltering heap.
Del

Well since you brought it up who needs the awning then to beautify the home.

simplicity is aways the correct answer.. use a manually operated system unless you don't have arms.

Yes, absolutely!

We had a 24' awning in PA from a company called Sunsetters. It was manual if I could had to choose again I would pick a mechanical one. The one we had was 10 years and held up to wind and rain with out any issues.