I've played with rebuild with Fear and his friends and i have got to say the balancing in this mod is really well done! and fixes all the problems with BTZ currently.
Also i since Techland is working on DL2 and DL:BB i really think that DL should just be handed to the community all community made updates, events and content would be pretty epic and will make DL last much longer. This will also make all the people who cant run DL2 really happy so :D
overall i think the rebuild is excellent and should be added into Dying Light.