I originally wanted 1.5ct for my 3.5 size finger, I thought that would be a great size for the long haul. I ended up with 1.17ct and I don't find it looks small on my finger after 13 yrs. of marriage.
But I did experience dss early in my marriage when I used to compare my ring to others where I live and felt like my ring looked small by comparison. Where I live there are women with very large stones, small for here is 1ct-1.5. For a couple of years I even stopped wearing my ring and sported a fake 2ct round until a friend of a friend told me it was an obvious fake. At that point (this was 6 yrs. ago) I stopped wearing the fake and put my real ring on again. Well then it seemed even smaller after wearing a 2ct lol. But then something happened, I'd say a couple of years down the line...my ring stopped looking small to me and I finally appreciated it as it's a very lively stone and really does suit my finger. If you focus on your own ring and don't take too much notice of other people's rings your own doesn't shrink anymore. It's not that I made a special effort to stop looking at other people's rings, as I do still notice the sparklies around me as it's impossible not to since I did mention I live in an area where there's a lot of wattage lol. All I have to do is go to the supermaket to see big e-rings left and right. But I came to realize that my own ring looks perfect on me and it's big enough. Maybe my taste changed but I don't really go for rings when they're over the top. I like big cocktail rings though but for an e-ring, I just like a more understated look that just is sparkly with out being too showy. I have felt self conscious signing receipts when I check out with my modest 1.17ct ring, I can't imagine how self conscious I would feel signing in front of the cashier with a huge flasher on my finger.