What are you planning on using the rod for?
Reason I ask is that I got a 6'6" Avid MLF for Christmas this past year. When I mounted a reel to it, it simply felt too whippy. I swapped it out for a 6'9" ML Extra Fast Avid and I couldn't be happier. I primarily use it for shakeyheads and splitshot rigs, but I wouldn't hesitate to throw small jerkbaits, etc with it.
I also totally recommend trying the reel/rod combo in the store before purchasing. My personal preference was that a 2500 series Shimano reel didn't balance very well with the ML St Croix's. For that reason, I went with a 2000 series Daiwa. You may be completely comfortable with the 2500, but try it out firsthand before buying