If you like Lightroom you should have no problems adapting to On1 developer, since most of the controls are the same, although the interface layout is a bit different. I hated the interface layout of On1 at first and I still find it a little illogical, but you can get used to anything.
Where On1 scores over Adobe is the development "Extras" where there are a number of useful tools, for example "Dynamic Contrast" which I find give On1 the edge over LR.
Using On1 does require a different approach to LR, and your workflow needs to be changed slightly, particularly for highlight recovery. There are a number of video tutorials about the basics of raw development in On1, both on the On1 website and on YouTube.
The addition of layers does allow one to do some things that you would have previously required Photoshop for.
I too used to struggle with Photoshop (I had CS6) and I'm not sure why, but find the interface of Affinity Photo to be more user friendly than PS.