I used to be a fan of greaseable joints because, in theory, they will last forever if you keep them greased.
The issue I noticed I had was , at least one passage on each joint would get plugged and the cap would dry out and it would fail just as quickly as a sealed joint.
I still have grease able in my rear driveshaft, but I have a stack of Spicer 1310 joints waiting to go back in when one or more of the joints fails.
Spicer lubed for life joints are what I plan on using in the future