I don't understand why there is so much fuss about how long a nipple will last...?
They are one of the least expensive parts you will ever need.
A nipple is an expendable and VERY easy to replenish part.
You remove it every time you clean anyway.
Buy a Hot SHot, try it, Buy an Ampco and try it.
Use what works best for you.
EVERY gun is like a woman, (sorry ladies, just my opinion) it will let you know what it likes, so don't fight it.