Ooh, I love LK Bennett shoes 
I've not had much of an issue with the sizing being too big or too small . I'm a 38 in LK Bennett, and all of the other shoes I own. I've found the sizes to be fairly consistent across all of the styles, especially for heels and sandals. I've found that flat pumps come up a little bit big sometimes, but not as much as half a size. Only one pair of my heels is a tiny bit big (again, not as much as half a size), but they are quite old now.
Certainly my Sledge in a 38 comes up the same size as all my other 38s. Sledge also has a little tiny rubber grippy strip thing in the back to help them stay on as well as they are quite high. I don't have Maddox so can't comment on those.
If you can't get hold of Sledge, Shilo are really lovely as well, just without the platform - I think they also come in taupe.

I've not had much of an issue with the sizing being too big or too small . I'm a 38 in LK Bennett, and all of the other shoes I own. I've found the sizes to be fairly consistent across all of the styles, especially for heels and sandals. I've found that flat pumps come up a little bit big sometimes, but not as much as half a size. Only one pair of my heels is a tiny bit big (again, not as much as half a size), but they are quite old now.
Certainly my Sledge in a 38 comes up the same size as all my other 38s. Sledge also has a little tiny rubber grippy strip thing in the back to help them stay on as well as they are quite high. I don't have Maddox so can't comment on those.
If you can't get hold of Sledge, Shilo are really lovely as well, just without the platform - I think they also come in taupe.