No comparison for Enterprise Readiness
For an actual comparison of "enterprise readiness", you would require two devices (or more) that actually have some level of enterprise ability. iOS still has yet to make any device that is enterprise ready or even remotely capable. It is true that you can add in some thrid party applications that make it seem sort-of able to work in an enterprise, but they are incapable of functioning with the same ability as a device, such as the Surface, which is based on Windows.
For instance, iOS still does not allow you to interact with the storage. They have now allowed you to add a file to an email, but only if it is stored in the cloud. This is NOT enterprise readiness, especially since I do not want my documents in the cloud where I do not have access to them from a corporate level. I cannot copy a file to the local storage, work on it while at 50,000 feet and then email from the next airport layover.
While resting or moving between applications, iOS always tries to refresh or shuts off the connection. Again, not entrerprise ready.
Windows 10 allows programs to be installed and run; not just Apps. Also, since it is Windows, I can run some of my home-grown software and function just the same as if I were using a laptop. iOS will never allow this.
It was not specifically covered here, but I am assuming the Surface still has a USB connector allowing flash drive access. Again, an ability that iOS will never allow. Another scenario: sitting in an airport with no public Wi-Fi (as usual since I will not buy it) and I need to hand a file(s) over to a colleague. I can easily move a file to a flash drive and hand it to them. (Oh, before you say use NFC or some dumb thing like that, they may be using a traditional laptop)
For these reasons alone, iOS will never be in my enterprise and has no functionality that is useful for my organization other than checking email while on the road, which I can easily do this from my phone.