I have been using Jabra FS258 with SE K700i and SE Z1010 for a while. It's really comfortable and everything is working alright apart from "wind stopping" issues. For example, if you are driving with the window open or walking on the street, the wind causing noises on the other end. In general, it's one of the best bluetooth headsets I have been using (Logitech...too big and not sitting well, Panasonic.... again.... not sitting well) so far. Well, will be better if you try to wear them before buying.