well, any decent player knows what cards you have anyway. sometimes it is not clear when they used a delay, but usually you know what they have and don't.
That's why I dislike it, it makes the game less strategic, but not only; if I use a blockade behind my lines in order to cut off a stack from a rich region, my opponent will be able to know where I used it. Same for recon cards, maybe I don't want my opponent to know that I know where he is. And even more, if I use a recon in a place he is not, he will get intel that I am not there too...