Dingle / Ring of Kerry / Blaskets

I disagree. You could definitely do Dingle and the Ring of Kerry in 4 days. I agree about basing yourself in Killarney though. Days 1 & 2 - do the Ring of Kerry. Two days gives you time to linger at the really spectacular parts, like the sections between Killarney and Kenmare and Sneem, or see some of Killarney itself like Muckross House or Ross Castle, or take a detour to Valentia Island.

Then head on over to Dingle for Days 3 & 4. It's about a 90 minute/70 km drive. Or flip it and do Dingle first. It depends on what direction you'll be driving in from. If you are arriving in from North Kerry/Limerick, do Dingle first. If you are driving in from Cork, then do Killarney first. The trip to the Blaskets will take up a big chunk of your day, as the ferries don't depart all that regularly and won't go at all if the weather is very bad. So plan when you go, as it's not like you can just rock up and expect a ferry to be leaving every 30 minutes.

It's such a spectacular part of the world, you could find plenty of wonderful things to see and do, if you spent all 4 days in either Killarney or Dingle. But if you plan properly, you can see a lot of what both regions have to offer, if you give them two days each.