I can't add much more to this topic than has already been stated but here's my perspective.
Stick with your medium action rod. Remember that it's not the rod but the caster that counts. I would suggest spending your hard-earned money on the finest instruction you can find than a new rod.
You could attend Joan Wulff's casting school, for instance, for about the same money as a high-end graphite rod. After her casting school you'll find that you can pick up virtually any rod and cast it well. In the long-run, it's about becoming a better caster and fisherman not who has the most toys.
BTW, when I attended Joan's school she was well in to her 80's and could still pick up just about any rod and with two loading casts cast an entire line off a reel with the backing showing. She could also hit a teacup at 50 feet. She's maybe 5' 4" tall and a slender woman yet she can cast as well as a man who is twice her size. It's the caster not the rod.