After I updated from 10.10.2 to 10.10.3 on my mac, the new Photos app was added. What i'm asking is can iPhoto do any thing that the new photos app can't?
Basically, should I keep using iPhoto or should I start using the new photos app?
No, the photo app has all all the features iPhoto has (and more) and apple has discontinued iPhoto. Not to mention the design is much better and it has iCloud photo library implemented in it.