What if it were glued on? The idea is cool, but there's no way I would want something surgically implanted like that. It's just better to be able to remove it when needed.
I say give it a try. It will be an experience, even if it's not the same experience.
I'd say a large part of the difference is mental. With an implant, your body internalizes the sensations, they're part of your body, your "one"-ness. With external sources, you may still feel the sensations, but they're not yours. Your body doesn't feel the fields, it feels an object that feels the fields.
