I just realised no one here has actually gone to the neapolis archaelogical park, which is one of the 3 main components of the site so...i'll give my impression.

The archaelogical site IS unfortunately nothing too impressive. I recall a Big greek theatre, a small Roman aphiteatre (both in a somewhat patchy state especially for Italy) and the ancient limestone quarries. Mostly I just walked around the ruins. It's not bad but I would say selinunte or agrigento are much better places to get a feel of the greek past of the island.

Nearby you can go check the catacombe di san Giovanni. They're pretty big and still has a few frescoes. I found them plenty interesting though I haven't visited many paleochristian necropolis to compare them too. I can say it's bigger but roughly of the same quality as the ones I saw in malta. In fact I wonder if they could be added to malta's twhs as a transnational nomination as they're typologically very similar.

Across the road you'll find the basílica santuario Madonna delle lacrime. A pretty interesting (and very photogenic) brutalist church.

I did not visit the necropolis of pantalica but I agree that ortigia IS the main element in the site anyway and it warrants inscription on its own given its importance and good conservation state. I found The temple turned Cathedral particularly enthralling and unique. The rest of the island holds a good baroque ensemble.