I don't think this is an either/or type decision on the awning our portable shelter, as both are useful in the right situations.
Most times we travel with just the awning on the van and use it as necessary for shade or rain protection. Equipping an awning to stop bugs is not something we want to deal with, having seen and looked at it in the past.
We also have a quite small, maybe 6X8, screenhouse that we take along if we are going someplace where we know there will be a lot of bugs, or it is a place the we would benefit from having it in our site while gone to prevent poachers, and we are going to be there multiple days. It stores tiny so every easy to carry with and not bad to setup and take down. We probably carry it only 10% of the time and use in less than half of the time we carry it, but very needed at times.