GS
Guy Schaller
Software Engineer for the past 12 years
it depends. If you have unlimited resources and an experienced development team, then it might make more sense to go native as it results in the best user experience.
If you are looking to build on a budget, or test a product, it will be faster to go with an hybrid framework (like ionic). A hybrid app can definitely save you time and money (initially).
You can also just choose to only build the app for either IOS or Android and build the second one after you tested the market and perfected your app.
Facebook originally tried to build their app as an HTML 5 app (hybrid) and ultimately were not pleased with the result (unlikely to see large, popular businesses choose a hybrid app). Here's a link to their story:
http://techcrunch.com/2012/12/13/facebook-android-faster/
In summary, here are the benefits of each.
Native Apps: better user experience, very slick looking apps, app itself is faster
Hybrid Apps: shorter time to market, Portability, one code base.
Good luck!