While I want to wait and see how things shake out, I can say my 72 level 7* IG-88 almost to G9 has a tank-like health profile now with even more offensive strength.
My concern isn't so much the power curve shift but how homogeneous the characters and teams will become. IG-88 should not be like a tank imho. His low health and protection were a good balance against his offensive strength and high health steal.
I didn't share the devs concern that characters were too fixed. They seemed pretty balanced, even when maxed out. Now, for a series of one-time costs, any character can be godlike offensively and defensively.
For the mods to work over time, there should be persistent costs to using them.
