Well, here is a little backstory:
Vexorian's jasshelper received a lot of criticism because the order of initialization. In order for things to work properly initialization-wise, we had to use module initializers.
Cohadar's jasshelper changed that order a bit (however, there are already a lot of resources already ordered in compliance to vex's jasshelper, which can be a problem). Cohadar also introduced for and while loops. However, the biggest difference was the speed difference and the advanced progress reporting (a better progress bar, and printing the steps). It has a lot more organization as well (source-code). However, it has some issues (eh, I forgot what exactly. Nes' knows the issues). Something about it breaking when you do some obscure code. Cohadar went inactive, so it didn't get enough support.
Anyway, I still use cohadar's jasshelper occasionally. The save times are quite nice. It is very easy to change between them in JNGP 1.5e and 2.0.X+ and above.