Switching to a different OS, can be jarring and cause panic, and give an uncomfortable feeling
But...you have to give it time, not just a day or two, that's not fair whatsoever, even one week isn't enough. It needs to be a solid month, and also not touch your other device at all, lock it up in a drawer, so it forces you to use the new phone.
See, this is my fear with switching to something for a bit. Beyond the heavy investment in the Apple ecosystem, years of use, etc I still have a 5S that I use for work daily. The people I've encountered that are the most frustrated with the Mac OS are the same ones that kept a PC handy so that they could quickly give up and go back. I feel like switching between the two constantly through the week (I only check my work iPhone once a day or so on the weekend) would make it an even rougher transition.
Either way, I posted on Facebook earlier asking if anyone was selling an S4, S5 or Nexus 5. Even offered to trade my personal iPhone 5. Figured the worst that can happen is I hate it and still end up with an iPhone 6 (or whatever it's called) if it's released later this year.
edit: And giving up the work 5S isn't an option. We're heavily against the Android OS thanks to security concerns in our organization. At this point we only have a handful of Blackberry devices with the rest being iPhones/iPads.