The answer lies in what you need X-C time for. As per definition both are loggable as x-c. Depending on you scenario I would log it like this.

Pre-Commercial License
I wouldn't log B-C as X-C because in order for X-C to count towards a rating you must travel to an airport >50nm. Logging everything as X-C might make it hard to figure out when you meet all the training requirements by you, your instructor, and more importantly the examiner come check-ride time.

Post-Commercial License
I would log everything to another airport as X-C to build towards the 500 X-C requirement of 135 IFR-PIC mins. At this point in my flying career I used a blank column and separated X-C >50nm for ATP requirements.