I put off western boots for years because they felt like a costume to me, like you had to also own a denim jacket with fringing and a reason to be at a barn dance. What changed was trying a pair on in a charity shop for a laugh and realising the shape did something genuinely flattering to my legs that no ankle boot ever had.
They're not right for everything, and I'll say that plainly. If you need to walk any real distance on wet pavements they can be a liability, because a lot of the soles are smooth leather or a thin rubber that was clearly designed with a horse in mind rather than a bus stop queue, and the pointed toe on some styles pinches if you've got wide feet or bunions, no amount of breaking in fixes that, it just moves the pain to a different spot on your foot. They also don't do subtle. If you want something that disappears into an outfit, this isn't it, it wants to be noticed, so under a very formal skirt suit it can look like you've wandered in from a different film. Where they do work, properly work, is the plain stuff people already own: straight leg jeans with the boot sitting over the top, a plain white shirt and a blazer, or a knee length dress in autumn with thick tights. They sort out an outfit that's gone a bit boring without you having to buy anything else new.
They age well if the leather is decent, which is worth checking before you buy rather than after. Real leather softens and takes on creases across the vamp that look earned rather than scruffy, and a light wax or cream every few months stops the toe drying out and cracking, which is the first thing to go. Suede western boots are a different, more anxious proposition, lovely in a shop, a worry in the rain, and I'd only buy them if you've got somewhere dry to leave them when the weather turns. On fit, go half a size up from your usual if the shaft is close fitting round the calf, because the foot tends to come up slightly small and your toes need a bit of room to not be jammed into the point. Check you can get two fingers down the side of your calf when you try them on, tight enough to stay up, loose enough that you can wear proper socks in winter without a fight.
A year or two in, mine have gone a shade darker at the toe and ankle where they flex, the stitching's a bit paler than the leather around it, and they look like something I've actually lived in rather than something I bought last Tuesday.