I am a convert from Spacemacs to Doom, and I have found that one of the main differences that sets Doom apart is easier configurability than Spacemacs. In Doom, there is still the concept of "layers," but IMO it is much easier to figure out what the layers are doing and customize them from there.

Also, I have found Doom to be much quicker (takes about 2 seconds to load, not using server/client) and less buggy than Spacemacs. I would highly recommend giving Doom a try!