We were just in Dauin last month. Pura Vida is nice, and I agree on the Balinese feel. Not too expensive. Did a day use of their pool and beach area the day we arrived because our resort had some maintenance going on that date during the day. Lovely setting. The restaurant food was good, and we ate at a covered / shaded table near our beach loungers. Drinks were not too expensive. Rooms and grounds looked nice, and we would stay there. Atlantis looked nice, but did not access the grounds or walk around. We stayed at Mike's, which we recommend, but it is a smaller, simpler place than the two bigger resorts you mentioned.
Dive resorts in Dauin are generally a few streets down from the main road that leads to the "poblacion" (central business area) one direction, and Dumaguete the other way. Dauin has the 200+ year old Spanish era St. Nicholas de Tolentino Church and remains of the old watch towers for warning of Moro Raiders from Mindanao. It's walkable and safe. Be careful in the dark along the main road, though! There are some other restaurants and pizza places in the area, too, but not a big nightlife area.
We were in the Dauin area for a couple weeks, and took two days off for exploring some of the sites. The Dauin and Dumaguete area has easy, inexpensive transport by trike or car / van rental. From Dauin to Dumaguete's "boulevard" area of restaurants near historic grounds and buildings of Siliman University was only 300 PHP (~$5 USD) each way and takes about 20 minutes or so. Just flag a trike or car on the main road. There are some good restaurants and lively bars along the waterfront on the Boulevard. There is nightlife (Why Not Bar, etc.), and some live music. Casablanca restaurant had good food and nice atmosphere. Avoid the Max's. Although, I love this Filipino food chain, the Dumaguete store is not good food, and not good service IMHO. If you want Filipino food, try the Dumaguete Pala-Pala Seafood House (half block off the main drag). It's a great place for REAL local style seafood at reasonable prices.
You can trike home fairly late in the evening. Make sure to negotiate a bit. The most we paid for return trip after a night out was 400 PHP (plus tip).
There are also lots of day trips if your non-divers want to visit area waterfalls (there are LOTS), hike or visit hot springs. A half-day car and driver rental isn't that hard to arrange either on your own, or through resort. It will be cheaper on your own, of course, but drivers are plentiful. There are enough waterfalls and hot springs and hikes to do a couple of full day trips if desired. Valencia area is great for half-day, as you can visit Pulangbato Falls, and the Red Rock Hot Springs and perhaps one other, and still get back on a half-day rental. There are many others. See attached Google Maps search. ;-)
Pulangbato Falls
Pulangbato Falls is an easy to reach, family friendly day out in Valencia. With multiple falls and swimming holes, here's all the info for visiting.
charliepauly.com
Red Rock Hot Springs
Red Rock Hot Spring in Valencia is one of the most popular day trips from Dumaguete City. Read our complete travel guide.
www.nopostcode.com
Finally, we spent a very enjoyable, inexpensive day trip exploring Siquijor Island (which you will see in the distance from either Pura Vida or Atlantis). We took an early trike to Dumaguete port (right by the Boulevard area), and got a ticket at the Oceanjet ferry office about a block and a half away. Took the 7:20 AM ferry (350 PHP / ~$6.00 each way...we bought round trip) and walked to the boat. It was about an hour trip.
Got a motorcycle rental walking distance from the dock in Siquijor. DM me if you want contact info, but it was only about 500 PHP for the one day rental of a great bike with lots of power. Helmets provided. We just bought a large "Coke" bottle of gasoline at a roadside stand on the way back. Roads well maintained, generally, not much traffic except in the town. No issues. It was great day driving the ring road around the island and visiting the beautiful beaches. Hiked to a waterfall with a couple of rope swings in the mountains. Had a blast.
Took the last ferry back at 6 PM (don't miss it!), had dinner along the Boulevard, and then triked it back to Dauin. Total cost (other than food and drink) was about $40 USD for two including fuel, tips, ferry tickets, and minor entrance fee donations at the beaches or waterfalls.
Siquijor Island Info
Siquijor Tourism: Tripadvisor has 870 reviews of Siquijor Hotels, Attractions, and Restaurants making it your best Siquijor resource.
www.tripadvisor.com
Hope this helps, but there are things for non-divers to do in Dauin. It all depends on what they like to do.