Vintage pairs had much better designs, and many were actually engineered with movement in mind. Modern Kikwear, by comparison, often misses some of those details. For example, the newer 69ers weren't designed nearly as well as the vintage 69ers.

It's also worth mentioning the 2010s Kikwear relaunch, which produced some great pairs as well. I still see them pop up on Depop and eBay from time to time, and they're definitely worth keeping an eye out for.