What do you like best?
Xcode has improved vastly over time. The best part of it is the way in which you can easily create the UI parts of the app and link them to the code. It is best if you can create a single UI that meets all devices, as that keeps your UI design simpler.
Taking an app from being just local to being for sale on the app store is now much easier than it used to be, with all of the difficult steps now done automatically for you by Xcode.
The ability to create libraries in swift and reuse them is very good, but also somewhat difficult to link in at times, so this can count as both a plus and a minus.
What do you dislike?
If you have to create a different UI for different screen sizes then that can be tricky. Also sometimes Xcode gets confused and you need to reboot to reestablish the connection with your device.
Some errors that you get when developing (especially linker errors) can be very hard to debug.
The problems you can have linking in user created libraries in swift (also see things I like best) is harder to use than it should be and creates excessive problems.
Recommendations to others considering the product
Really the only choice you have if you are developing for iOS and don't want to be reliant on third party solutions.
What business problems are you solving with the product? What benefits have you realized?
Creating apps for sale on the Apple app store for both b2b and b2c systems.