I'm with Angie on this one. I have a linen dress too, and when the temperatures (and humidity) sores, I want to wear it everyday. Like everyday. It's not my best dress, it's not the best fit and it's not the most flattering, but it's a workhorse.
Linen is stiff. When (and if) you take this dress for alteration, Princess darts at the back could make it just 'fitted enough' at the waist for you. I do this to almost all cotton & linen tops & tunics....without it, the top just looks like a tent on me.
I really like the print & color. Also, when it's crazy hot, I just want to wear one simple opaque piece and get on with my day. In fact, the dress looks good with flats too (in case you want to wear at home).
I say KEEP. I see you wearing this to a summer barbecue, for lunch or dinner, and even shopping trips - all with different accessories. This dress will be easy to dress up or down