Thank you for sharing!
The Nexus 5 is also my daily driver. I'm not in the market for any new phone right now (can't afford it and love my Nexus) but the iPhone 6 has me a little tempted.
Like you I think the size of the 4.7 inch iPhone would be perfect and I'm really frustrated with the ever increasing size of the current android flagships. Going up in size to the nexus 5 was a stretch for me and I daily encounter situations where I think to myself that even a marginally larger phone would be really inconvenient. I would also LOVE to finally have a great camera on my phone. And of course with an iPhone you don't have to worry about carriers or bloatware or support which is really important to me (That's why I have a Nexus 5).
But I prefer android especially for my phone (I have an iPad Air too).
Things I'm worried I'll miss:
Widgets - quick glanceable info like my calendar in a month view (any other view is useless to me) is very helpful. Right now I have a whole home screen dedicated to this.
Being able to manage WiFi networks easily. - thankfully apple let's you turn WiFi on and off in quick settings but to manage WiFi networks you need to open the settings app and there is no other way to get to settings (a shortcut to settings from quick settings would be useful)
The back key - I've run into situations on my iPad where I literally did not know what to do for like 30 sec because getting back to the previous screen or dismissing a dialogue box was so non obvious.
Having contacts shortcuts- the favorites implementation in iOS 8 in the multitasking screen seems messy. The main person I communicate with on a daily basis is my fiance and I like being able to unlock my phone click on a picture of his head and go.
Lack of customizations - I don't root or ROM anymore but I still appreciate customizations like launchers, custom gestures (I can turn my phone off with a swipe up from the home bottom which is super convenient), etc. At least 3rd party keyboards are OK now
I'll wait until my Nexus 5 dies to see if android can pull back (just a little) from the screen size madness. Hoping I can stick with android but we'll see.