This mod definitely helps you out with the tower defense type of levels (and helps almost max out a few gold heroes). The rest of the game is pay to win, but overall great just like whiteout survival, survival tactics (an oldie), state of survival, etc the list goes on.
I found that I could save the progress by using email, uninstalling the mod, installing the original, and logging in, and then vise versa with the mod.
The game just updated an hour ago, so I assume the mod needs to be updated. Currently running a good alliance with some good players.