3rd party will be a range of models and years. The pictures will rarely be exactly what you have in front of you, and are often grainy and difficult to make out fine details. The steps will also be generic and will have a step or be missing a piece because it was on the 95 model, but not the 2001 model, or some other such nonsense.
It was the same with Clymer manuals for motorcycles. Never as good as a Honda Service Manual.