My advice would be that if weather was going to be good and there will be enough people in the caravan to warrant the extra space then i would (and have)put up the full one.
If weather isnt cracking then go for the porch awning with storage for wet shoes and coats.
We are going to try our outdoor revolution evolution 450 for the first time this coming week. It's supposed to be almost as big as a regular awning ( bigger than on a small van) but with only 2 poles, much easier and faster. Looking forward to it and will feed back. :-)
We've got 3 kids and 2 dogs so the extra space in the awning is really handy but none of us really likes having to put it up lol. Ds likes to sleep out there too but we have decided that for 2 night breaks we won't bother but for anything longer we will. The awning is really handy for taking wet, muddy stuff off and a great place for storing it too. If we don't have the awning up and it's raining all the muddy boots and wet coats have got to go somewhere so i think if the forecast is bad even for a 2 night break we will have to put up the awning. We haven't got a porch awning but that is where it would come in handy.