Funny thing, Apple first kills the usability of SIM cards:
- MiniSIMs are quite easy to handle, although there is a tendency that SIM cards get lost when they are not in the device.
- MicroSIMs are not so much fun, but one can usually handle them by handling them slowly and carefully. These are somehow understandable, as they DO provide some tiny volume economy over MiniSIMs, and they are roughly the same size as MicroSDHC cards.
- NanoSIMs are basically not changeable quickly on the road, you happen to need special tools and so on. The complexity of handling them stands in no relation to the volume savings.
Reality is that by introducing 2 additional formats for SIMs, their primary purpose (making linking a subscriber with the hardware changeable) is already compromised. Happened last week to me, at a meeting, where we had a NanoSIM from the good network with LTE coverage, a iPad mini that was not very reliable at tethering (well a dozen guys mean roughly 12-24 concurrent clients, that's way beyond of an iPad), and a Mifi hotspot that was very reliable, but could not use the NanoSIM, hence we ended up tethering to the Mifi hotspot that did WLAN forwarding to the iPad. Still did not work perfectly, but restarting the iPad hourly let us survive.
Now, let's take a perspective:
An iPad 3 mini is 200x134.7x7.5mm == 202050 cubic mm.
A MiniSIM is
285 cubic mm, that's 0.14% of the volume.
A MicroSIM is 136.8 cubic mm, that's 0.07% of the volume.
A NanoSIM is 72.52 cubic mm, that's 0.04% of the volume.
So the designers have gained 1/1000th of the volume of the device in exchange for the primary purpose of the SIM, easy changing of the subscribe identity. (Changing a MiniSIM is something that can be done easily enough when driving. Changing a NanoSIM is an engineering task for home.)
Even for a small phone like the iPhone 5s, the volume saving from MiniSIM => NanoSIM are 1/250th of the volume.
Apple to the rescue
Now that the design purpose of the SIM was gutted, Apple manages to ride to the rescue of it's user, by introducing a software switchable SIM. It's clearly more convenient than switching a NanoSIM. The convenience win is not so great compared to switching MiniSIMs. And even better, it binds the customer so much stronger to Apple. Well, better for Apple, I don't see the benefit here as a customer, but then I try to stick to user-friendly devices, at least for my purposes, and that means no NanoSIM devices for me.