Granada is a visually attractive city. It's also a mob scene, with tons of vehicle traffic belching diesel fuel and honking like it's China. I wouldn't pick a hotel anywhere near the Central Park because of noise, smog, and congestion.
Granada makes a good base for Nicaraguan travel. There are many competing tour companies offering good deals on exciting excursions. It's also a good place to take care of any needs you might have. But the city itself?, as a tourist attraction? Meh... One day was enough for me.