I'm astonished that it appears that over half of Britannia's passengers appear to have endured an unpleasant experience. Either their standards are infinitely higher than mine (possible) or they are more sensitive to disappointment (equally possible).
I've seen the decor complained about - others found it pleasing.
I've seen the food complained about - others enjoyed it.
Cabin was fine, the balcony was adequate for our needs regarding size, the overhang was significant.
Please be aware that if you are flying home on the last day and book an excursion you might find that you have to cancel when you see the time at which you have to leave for the airport. This happened to us. I found the Shore Excursion staff that I spoke to somewhat cold and unsympathetic.