Will Acts 4-6 have the same difficulty as Cruel 1-3?

So here it is:

Either I accidentally made a completely op build, which is unlikely because I never played PoE before and had no idea what I was doing, or is Cruel Act 1/2 pretty easy?

I am level 52 and I am completely frying through everything, even the bosses in Cruel so far. The final fight of Act 1 Cruel was a difference of night and day. Most of my equipment is 10 levels lower than my player level and is nowhere near optimised.

I hope the power progression is a bit different when Acts 4-6 come out, because right now the game has lost its nice slow and methodical gameplay. I can just blast through everything with my Lightning Merc, using almost nothing but Galvanic Shard.

Was I just lucky with my build or is this normal?