My personal and hypothetical answer to your question is most probably it will hurt. Because the calf gets much pressure when we stand or walk, it is possible that an implant would eventually hurt.
I do not know anyone who has done calf implants, so I have no personal feedback to share, but I agree, it sounds painful enough. I suppose you can get used to the implants, but I can't imagine what it would feel like if you have to stand or walk a lot.
I think on the actual operation it wouldn't hurt since there's anaesthesia but after the operation, there's a big possibility that you'd have a hard time walking. You'd probably be in bed all day.