Adam, What kind of furler are you talking about? Is it a new one or a used one. Is it a Hood or some other brand?
Some people complain about the difficulty reefing a continuous line furler as they have a tendency to unfurl themselves if the line isn't really tight or the drum isn't tied off to something to keep it from unrolling. Other than that, there's not a lot of difference in how they operate and how a single line furler operates.
You do usually have to have the furling line spliced in place. So unless you can do the splice yourself, there is likely to be an extra cost associated there. Plus, you need to have special lead blocks because you have twice as much line running up and down the deck.
Having said all that, unless you are getting a real good deal on this unit, I would probably advise you to just go with a single line furler. There are more choices of brands, they are simpler to reef and you don't need to know how to splice.