Main pitfall will be the food, if you're not used to Scandinavian food then have a few burgers at SFO or better. You'll find the IFE to be very mediocre compared to other airlines, might want to load up your laptop with some movies. The WIFI will be better than most alternatives if you value that. The UA lounge at SFO is a total joke while the CPH lounge is mediocre at best, not worth spending your time. I'd arrive right on time in SFO and any layover time at CPH to be spend at one of the restaurants.