Originally Posted by Grondie
Buttons don't get stuck and are genitalia-friendly.
but can have awkward stretch symptoms on the fabric around them (especially on raws) if the denim is worn tight around the hips.
In fact, I hated zips on denim and had a hard time getting used to them, when I started wearing Thanaz. But now, I am fine with them.
For me its undecided. Both have their advantages and its not really visible.