Aperture was also my favorite app. I've tried almost every raw converter around and found that Capture One is the closest to how Aperture worked.
Other than that I've been using Affinity Photo for many years because I just never got along with PS (same for LR). I've tried Pixelmator and it seems to work quite differently when it comes to layers and adjustments – which is a good thing because not everybody likes it the same way. Affinity wants to do as much as possible in a non-destructive way. It offers "Adjustment Layers" like contast, saturation, perspective, liquify etc. that you can stack above your base image layer. You can brush the adjustments on to certain areas of the image or apply it to the entire image. At any time you can go back to that adjustment layer and change it. In Pixelmator it seems to work differently: First you'll make a selection on your image layer and then apply an adjustment to that selection. But once done, afaik you can't change that any more. In order to do that, you'll have to first duplicate the image layer with that selection, and then apply your adjustments to that new layer. So Instead of adding adjustment layer, you add image layers which have their adjustments attached to it. (Perhaps there is also a different workflow, but that's my finding so far after trying PP.)
