I'm about to pull the trigger on a 7' mh micro magic and a lews tourney pro for an all purpose rod to replace my current setup. But on the tackle warehouse website it has two selections: casting and cranking. What's the difference?

The action of the blank. Though duckett doesn't actually list their rods actions. General terminology would be

Medium heavy with a fast or extra fast action.

That's your basic casting rod.

Medium or medium heavy with a moderate action.

That's your basic cranking rod.

The moderate loads further down the blank and helps with hooks not pulling out on treble hook lures.

You want the casting rod for an all around general use rod. You can throw a big mix of things on it.

'Cranking' version will have more bend.

Rippin - Lips gave you the word, an all purpose rod is going to be the regular casting rod, cranking rods are for crankbaits. The difference is in how they bend, most cranking rods are considered moderate or slow in action and that means they bend further down the blank and usually deeper. The reason the deeper bend is good for crankbaits and lures with treble hooks for the most part, is because treble hooks won't always penetrate and often there is only one point that is actually holding the fish. The deep bend keeps constant pressure on the fish, think of it like this, say you had 2 lines in your hand, 1 was tied to a stump and the other was tied to a limber willow branch. When you pull on the line tied to the stump it doesn't move, you will continue to apply pressure until the line comes untied or it breaks, that's it but now you pull the 2nd line tied to the limber willow branch, what happens? The willow branch will bend as you pull and the harder you pull the more the limber branch bends but it bends so much you don't break the line like you did with the stump, instead the branch bends and it makes it much harder to get the line off.  The reason you don't want that for an all purpose rod is because while it is great with a treble hook bait, The rod will bend too far most of the time making it hard to set the hook on Texas rigged worms, creatures and jigs, the stiffer casting rod will "shut-off" meaning when it hits the backbone of the rod it will bend very little and the power will go through the line which will provide enough force to drive a big single hook through the jaw of a bass.

You will love it I have the duckett micro magic 7 MH (casting) on a Lews tournament mg  and I absoloutely love it, very smooth light weight rig.  You will not be disappointed, if you can wait to October the new micro magic pros will be out and this revised version will eliminate all the problems the first series had.