With Meermin I am comfortably a 9UK (*slightly* loose, but comfortable). With the SL 199 last, I have a pair of 8.5UK. They were tight at first, but have gotten comfortable after a dozen wears or so. I find the the SL shoes to be stiffer, especially at first, which made the first wear or two uncomfortable by the end of the day. At this point, however, they fit well. They still feel tighter than my meermin 9UKs (a boot in Olfe and oxfords in Park).