In my very limited experience with Barker's, whilst their construction is perfectly acceptable (channelled (but not hidden), goodyear-welted shoes), the leather quality lets them down. They do have an "anniversary" range, which I have heard uses better leather, but their standard calf-leather shoes crease quite badly. The creases on my only pair of Barker shoes are quite large, which I understand indicates a lower quality of leather. In comparison, the leather on my Berluti, Edward Green, Santoni and even C&J Handgrade shoes has very fine creases/wrinkles.
However, as I mentioned above, given that the area of the vamp that creases is made of suede on this style of spectator, I suppose that wouldn't be an issue for either the Loake or Barker shoes as suede doesn't show creases very much and they can be brushed after wearing.
Anyway, if I were to compare my pairs of Loake 1880 and Barker's regular line of shoes, I'd give Loake the edge in terms of quality.