You have to always take sizing advice with a grain of salt as feet are just different. I'm a 8D TTS and I went with a 7.5 for both the 2030 and 2045. I feel I maybe should have (or could have) gone with a 7 for 2045, but the 7.5 with thicker socks is ideal. But...I could NOT have gone down to a 7 in the 2030. Most advice is to stick with the same size in the 2030 and 2045 but my feet (or preferences) might be different.