I use lake reed flour as well as grain flours. There does not seem to be any variance in the quality of products created from their use. Nowadays I only use flour in a few cooked dishes because the food value of the bread created, regardless of the type of flour, just seems not worth the time, trouble, and work involved.
Overall, I would say reed flour IS worth it mainly because it costs nothing other than time gathering, threshing, and grinding to acquire. I've had reed plants waiting in a cellar for several years now to be threshed and they still have not gone bad.
For the record, I recommend storing peas and beans in a cellar. I thought that they'd last forever, being just dried product. However, they will spoil. I never replaced them, having so many roots from the various herbs which are perfectly acceptable as 'vegetables' in cooking recipes.