Aluminum aka Alloy nipples have a bad rap for cracking, corroding, and freezing in place. This is the result of a few issues that are easily overcome.
One: DT Swiss gives you clear anodized aluminum nipples when you buy their nicer spokes. So bikes shops have them laying around. Clear and light colored anodized nipples corrode more than darker anodized colors.
Two: 95% of bike shops do not grease the rim / nipple interface, nor do they dip the nipples in a machine oil of any sort. Skipping this step can even cause binding and corrosion with brass nipples, but it’s faster and nastier with alloy nipples.
Three: Lots of wheel builders refuse to use a spoke tensioner, however, uneven tensions lead to nipple failure.
Last thing: Spoke prep. Many wheels are built with improperly prepped spoke threads (probably not prepped at all). If you are not completely covering the threads with some sort of protective coating, ala Anti Seize, Spoke Prep, etc, you are just asking for the spoke to bond in the nipple. We use spoke prep and gear oil nipple baths on all our wheel builds, regardless of the nipple type. This, combined with an evenly tensioned wheel, results in a reliable, and serviceable wheel regardless of nipple type.
We use the Sapim nipples, mainly because they’re as good as any we’ve tried AND come in fun colors. Stay away from the lighter colors if you live in a salty area. If you don’t live in a wintery climate, get whatever! Except clear silver, we don't even stock those (just get chrome plated brass nipples). We are happy to do a funky/custom color pattern on your wheels. Get a wheel quote today!