I use RPG Mod.
Click on banner sig and there you will find all the reasons I use it. Of course, I made it for myself specifically.
But, there are still good reasons to use it if you want to create an RPG that includes at least the ability to use weapons when you want them or not use them if you don't.
Personally, if I didn't develop FPRPG games then I would wait for the migration and maybe use FENIX mod as the migration is going to have a lot of what FENIX has but probably not all. I wouldn't be able to explain that difference.
Project Blue, I am not that familiar with but it has a lot of Ply's Old mod and there was a lot of good thing with that. A lot of people liked the dual wielding guns.
So, it boils down to what you want to do with your games. There isn't just one mod that will do everything. Even the migration will not do everything that the other mods do but it will have all the most favored features.
Get all of the mods and then get BlackFox's program called Mod-It (it's free) which will transfer mods back and forth in a click depending on the mod you want to use for the particular game you are developing.