ND filters

I'm in the market for a ND filter after not being able to slow my shutter down while trying to capture some water fall action. Is there a difference in variable filters vs the step down style of filter lens? Found this one on ebay that I'm interested in: Hoya Variable

Thx

I have used this one and I am happy with it. You have to realize that turning it all dark will result in some weird stuff (it is like overlaying two circular polarizers), so I would caution on that. But other than that I am happy with the Marumi. Good glass, and cheaper ....

I had been using a variable with good result until day before yesterday. I found it to be pretty much useless to me on the beach in full mid day sun. I ordered a b+ w 3.0 (10 stop reduction) today from amazon. I will get my shot, now.

this is the one i have CAMERON 49MM MC FADER ND FILTER 8811049 it works very well for what i use it for.