I liked Davao, it is a large city with a lot to see and do. As an American visitor, I admit I got a lot of looks that made me uncomfortable, so I recommend you stay on your toes and be aware of your surroundings and use higher than normal precaution when moving around in the city. Still, most people are friendly and polite.
The costs are very reasonable in Davao, (even in the SM Lanham Mall which is connected to the hotel), especially when compared to Manila.
There are a lot of fresh fruits and vegetables, and great places to eat in Davao.One of my favorites was the Giardino Gelato stand at the mall. I ended up stopping by there every day while in Davao and trying a new flavor.