Re: LTE is good for those of us that like to exercise outdoors
But what's wrong with taking your phone on your ride? I go on long bike rides but I always have my phone with me, either in my saddlebag or in a cheap rubber mount on my handlebars. Having a watch that could make/receive calls wouldn't be of any use unless you want the leave the phone at home.
Maybe when you say you ride "off road" you mean in a lot of mud or there's a good chance of the occasional spill that make break your phone? The watch being waterproof to 200 meters or whatever should protect it against mud, and I suppose it is probably more durable than phone if you fall...