I can understand that. The idea of the coil made me wince for a long time and then I was left with little choice - so I took the dive.
The only negative that I've experienced with it is a reduction in my sex-drive. However, that's probably the type of coil that I have, rather than something that's common to ~all~ coils as a side effect (the mirena isn't usually recommended for women who haven't had children or who are in my age range).
The positives, however, far outweigh the negatives: I only have to worry about it once every 5 years, I don't have periods, I don't get PMT, period pains or anything else associated with "that time of the month" and a multitude of other positives too.
Personally, I'd have had a coil put in years before I did, had I known!