My sons' school (Catholic School) used to have just a dress code and they went to uniforms a few years back, because nobody had the guts to enforce the dress code (no jeans collared shirts, no words or logos, only longer skirts for girls, nothing sleeveless) So, they went to a uniform that has many different varieties, for the boys there are 3 colors of shirts available in polo (short and long sleeve) and dress shirt - same for girls with the addition of a traditional schoolgirl (perv bait) dress. and all must be worn with Khaki, Blue or Black trousers (walking shorts in season, compliant skirt for girls) So, there is a huge variety of "unifromity." Add to that, kids have taken to accessorizing by wearing different color t-shirts or even long sleeve shirts under the uniform shirt. So, it's not very unifrom looking in the end.
As for the argument about it blending haves and have-nots (and we have many kids on financial assistance, so it's not a rich kids only school by any means) the haves always have a way of showing what they have, whether it's shoes or jewelry or whatever, and the have-nots can look pretty disheveled in older worn out and sometimes un-cared for uniforms. So, to a degree you know which is which, just like you would in public school.
One good thing is that price isn't so bad, it's very comparable to what we would have to pay for clothes under the old dress code, but yes it does suck when a kid shreds one. We're about 3 months into the school year and have already lost 2 pair of pants, 2 shirts a pair of shoes and a sweater (and that's all from one kid)
Some public schools are going to uniforms too. not sure what success they're having.
I think a well thought out and enforced dress code does the same job.