Oh yes, many times. I currently have 3 pair of Issac Mizrahi loafers in red, black and grey because they are so comfortable and I can walk forever in them.

I've only duplicated boots once -- the same Matisse booties Angie has, but one in the leopard print and one in red. In retrospect, I'm not sure the red ones were the wisest purchase. I haven't worn them much. Also, something about my feet has changed a bit, and they are not as comfortable as they were a few years ago. I have other dark red booties that are not as refined in shape but I wear them more.

I have duplicated sandals -- rose gold and black Cole Haan flat thong-style sandals that have been summer staples for 4-5 years. No brainier! I also have duplicated of some perforated slip-on sneakers, one in silver, one in mint. I have worn both of those quite a bit, but not as much this year as last. And I've duplicated walking shoes (left the old pair at the ranch), and of course running shoes (I think I'm on my eighth pair of Brooks Ghost runners and I dread the day they are discontinued!).

Oh, yes. For sure! If you love a style and the fit and comfort is good then why not. Having shoes or booties in multiple colours doesn't bother me in the least.

I've been tempted to for one pair, but didn't. Between foot problems and feet changing size slowly over time, I don't have an accurate grasp of what will feel the least uncomfortable years from now.

I don't think I have duplicated booties yet, but I sure have multiples of shoes, sandals and sneakers. Same reasons as others: team fussy feet and hard to find ones that work. I am a shoe person, so I like to have options in different colors and styles. I usually do what Suz suggested: be sure that one pair plays well over a little time before a firm commitment to duplication. Usually, I find one pair gets a bit more wear than other. I am okay with them both being in rotation with somewhat different frequency. I love choice and the hunt for footwear needs to simplified around here.

Those booties are gorgeous.

There are more shoes that fit me now than 16 years ago, as I need something to hold my ankles in. No loafers or pumps for me.
So, a year before an event, I bought 3 pairs of shoes. I wore the two black pairs for every nicer occasion until I wore them out. I thought the third pair was a mistake, but now I am loving it even more, especially now that my hair is gray.
I also purchased sandals, first in one color, then a year ago another from Zappos when I found out they were no longer on the Zappos or Nordstrom website. And I just duplicated them.