We got our awning from Roche and when we discussed it with them they suggested that we have the full-cassette option as this would protect the awning from winter weather (which in the UK is a big thing). It was one of the best investments we made as we kept going back on our decision and then deciding to have one etc. If you're unsure, get some advice but I would recommend a full-cassette as it has withstood one of the worst winters we had and some very high winds.
Hope that helps.