I have a 6'6" medium fast action for 1/4 to 5/8. Got it dirt cheap for jerk and topwater but I hardly use those techniques.

You think it would be good for 1/2oz spinnerbait and bladed jigs?

I have a couple 6'6 rods, and think they are too light for 1/2 spinnerbaits and bladed jigs.  I can fish 3/8 spinnerbaits or flukes with much more comfort if I don't have a popper tied on them.  

You might be able to get away with a 1/2 oz spinnerbait, but I think it would make for a long day with a bladed jig tied on due to water resistance.  

That is a good rod for 1/4oz to 3/8oz spinnerbaits and chatterbaits  because 1/2oz is going to strain it to the point of the bait over powering the rod. This also depends on the rod manufacturer, I know Falcon rods are spot on with the ratings meaning if the rod is rated to 1/2oz, you will find it tough to use on 5/8oz anything. You are correct, jerkbaits and topwater would be where this rod shines, but in addition to what was already mentioned, it would be a good fluke or senko rod, and it would be good for square bills and lipless that are in the weight range. I like the 6'6" length, but in casting rods the MH is more versatile but the medium does have its place so use it on all those things, just keep the size of the baits down and you'll be good to go.