Salmo G has it right. I've had fast action rods (tip flex) feel like mid-flex and vice-versa. So much depends on your casting stroke. Generally speaking, a fast action rod will help a proficient caster drive a shallow loop through the wind better than can be done with a mid-flex rod. Bottom line is to try out lots of rods at the fly shops and see what feels and casts the best for you....don't get caught up in the marketing hype. I have a few lower end rods I've built that gram for gram, inch for inch, are my favorites.

Although, I must admit, I've been anxiously awaiting for someone to offer the "Q-axis, Nano-Modulus Scrim, Mega-fast" series!