I am looking to get a drop-shot rod in a casting model for under $200.  I already have a ML Avid spinning reel that works alright for drop shots but I tend to always have a shaky head rigged on it so I was considering a dedicated DS rod.  My questions are:

1) Is a dedicated DS rod (ie a rod that was designed solely for drop shotting) that big of an advantage over any old ML rod?

2) If so which DS rod is the best in my price range?  I usually fish with Loomis equipment but their DS rod is a bit pricey for a technique I don't use ALL that often.

3) Would I be better off saving for one of the GLX DS rods or the Cielo DS rod or is the $100+ difference no big deal.

Thanks for your help!  

Most DS rods are X-fast.  Look at something like the 6'8" Med power X-Fast action from St. Croix and let it double or triple as a topwater rod or a shakey head or finesse worm rod. (anything you like on an X-fast rod)  For that matter, any X-Fast will work well so if you are a Loomis fan, that would be fine also.  

If the Crucial casting DS rod is anything like its spinning sibling then it will be an amazing rod for the job.  I have a 6'8" Crucial DS spinning rod and it works wonders DS'ing.  Also does great with a #5 shad rap

I have the 7'2" spinning version of the Crucial dropshot rod, and I assume the casting version is equally good. I'm very happy with it, and actually, like you, don't dropshot too often, but it serves many purposes, especially for throwing light baits in relatively open water. It doesn't have too much backbone, but it's very light and sensitive.

Out of curiosity, why would you want a casting dropshot rod instead of spinning? It seems like it would be an unnecessary hassle...