The only negative part is it does attract fruit flies. I keep them in a spare room in the garage. I use a coffee filter with a rubber band to keep them out of the vinegar during the process. One I used cheese cloth, but I must not have had enough layers, so apparently some of the fruit flies got in, laid eggs, and I saw these really tiny fruit fly larvae moving on the inner sides of the jar ( above the vinegar). needless to say I dumped the batch and no longer use cheese cloth as barrier .
If I have a mother or some raw vinegar I sometimes add a little to the new batch to speed it up ( as Bliss mentioned), but I've had great success with ( and without ) adding it, so I don't go out of my way. It's only if I have and if I remember .
