Coachman are generally regarded as a better built caravan, but heavy, although there do seem to be a number of complaints coming up on the internet which makes me wonder if the new management have let things slip a bit. They are very nice caravans though.
Bailey are cheaper and lighter but to me less stylish, but appear to be average in quality. Both use modern construction methods and are well equipped.
Frankly I would go with your heart and buy the one with the style that suits you all other things being equal.