I purchased a 6s ahead of iPhone 7 launch because of a good price deal. Actually after seeing the keynote, I didn't regret my purchase because I had a better deal and key features in iPhone 7 like digital home button, no audio jack, water resistance, dual-camera, 2-hour improved battery life don't matter that much to me personally.
You can still get a 6s and be happy using it, if you want to save some money. Go for the iPhone 7 if you want to use the Apple AirPods (wireless earphone), take advantage of water resistance, and have more options in photography