Even though this is potentially a "Can O' Worms" Topic....I'll play....as I have opined before in several posts, there are many theories and preferences as to how an angler may prefer and perceive a dry fly presentation....some are of the thought that slower and more delicate, full flexing, soft tipped, rods are best for dry fly work....where others are of the thinking that faster line speed to unfurl longer leaders and allow such prior to presenting the fly upon water is preferred, both are used in specialized individual techniques, in days of old it was the same...softer, slower rods were often thought of as "wet" rods by some and "dry" rods by others....and the same went for rods with more backbone. As technology advanced, we became aware of "recovery" and a rods ability to come back to static in both body and tip...and began to understand that better recovery, lessened undulating tendencies within extended line and further loop formation, similarly true for both faster and slower rods. I often refer to the separation of opinion as those who prefer slower dry rods and those who prefer faster dry rods as slow dry and fast dry application rods. Although I may take authorship of these terms as casual descriptors for angling chat, I really use them for lack of a better specialized naming...and to describe the attributes of particular gear so a person listening or reading will have no confusion as to which attributes a particular rod has. I personally have little preference for one action over another, in such that if the rod meets the circumstances at hand to present the fly accordingly then I deem the rod serviceable for the task. However, my caveat, is that I absolutely have a preference for rods that are tuned for appropriate recovery....and further, this doesn't mean necessarily the most modern rods available, I have opined that many early rods, even slower action rods, had quality recovery. Others, did not. I do not like a rod that reverberates endlessly upon stop and much like sound waves passes that on in kind to the line and loops being thrown. So for me, the recovery and stability of a rod trumps perceived action of a rod. Arguably, I will contend that stability and recovery are paramount attributes beyond slow, medium, medium fast, or fast rod actions. In regard to the above, I do not believe there is a right or wrong belief in a "best" type of rod to present dries and rather contend that the rod should match the environment of use and be capable of it's job....if it is, whether fast, slow, or in between, the rod is serviceable. Personal preference of how one perceives a rod to "match" ones personal needs and style of fishing may have been the leading in to several trains of thought in regard to what constitutes a "dry" fly rod, but in all actuality, I cannot see, other than preference, or applied to specialty technique, a way for an angler to prove superiority of one design over another. Short answer- for me, only me, your mileage may certainly vary, give me a rod with solid stability and recovery and I'll make any rod with it work respectably to present dries....regardless of perceived action.
