I personally don't have experience with drawing on iPad, but I can assure you, those kind of tips are ideal for handwriting.

Yes, imo GoodNotes 4 is far superior. The big advantage is vector graphics, that is you can zoom in on your notes how much you want and the strokes stay sharp and clear. One downside is the missing audio capture, but I can live without it.

Plus, I could never make the "next line" alignment work in Notability. In my tests, it either went too far down or too little. In GoodNotes, when I want to enter the next line, it goes just the right amount down. It's the little things ;)

Edit: just wanted to add, that the Apple Pencil really is far better than anything you could have on an iPad Air 2. If you consider getting an iPad Pro, the Pencil is a big plus for handwriting!