Honestly I think it's all in the head. Sometimes I think 43mm Aquaracers are too big, but my 45mm Carrera is fine. Sometimes I think my 40mm Formula 1 is too small, but my 39mm Kirium is fine. Some watches fit on the wrist better than others, I do think my 38mm 6000 Series is verging on too small, but there isn't a bigger option as far as I'm aware - and I like it, so I live with it. It's also quite thin, I think if it was a few mm thicker it would help a bit...
I've noticed particularly when you go in a shop and try on a watch, it can really depend on watch you were wearing when you went in. If I go shopping with my Heuer01 on, everything seems too small...