The advantage of the cabin top traveller locationis that it opens up the cockpit for people. If you cruise a lot with guests, having the mainsheet out of the cockpit is a plus, and you have hands on board to handle the sheet. Plus the mainsheet does not cross the cockpit durning a gybe.
Having the traveller in front of the helm is a plus for singlehanding, as the main sheet can be right at hand.
I singlehanded for years a boat with a cabin top traveller and found it a minor inconvenience, just another item to be one step ahead one.
Like most boat subjects, this choice is a matter of trade-offs, you need to decide which are most important to you.
Certified...in several regards...