I needed some dressing looking shoes with my suits for work and these are the most comfortable pair of of my six pairs that also look extremely classy/dressy.  I usually weara  10.5 shoes (10-11 as I have wide feet) and I tried the 44, but they are too large as Ecco's tend to run large so I got the size 43 and they are perfect for a size 10-11 us mens foot.  You won't regret it!