Finally got my iPhone 6 two days back! Lovin' it. Yes, getting used to the larger screen with iOS but since I have tried my hand at some Android phones recently (e.g. HTC One M8, LG G2, etc.), the big screen is not a pain point. Got the 128Gb Gold version as AT&T in USA sells it for $28/month on the 24 month Next plan and gives you a $25/mo credit for having a Mobile Share Value plan; basically making you pay only $3/mo on the 128Gb iPhone 6. Having the 128Gb is a big plus since my music keeps growing and I always have to make the trade off by deleting certain albums/songs. Now I can happily store them up.
My last one was the iPhone 5, so this is my first experience with Touch ID and its freakin' awesome to use. I can now set a complex password as backup for my Touch ID (earlier setting complex passwords meant I had to type them in every time to unlock; now with Touch ID, I only have to enter them when the phone restarts or if my Touch ID for some reason stops working which almost never happens, at least for now). The higher resolution on the iPhone 6 compared to the iPhone 5 means that apps/images/videos all look sharper and with more clarity. Haven't made use yet of features like the M8 processor. The phone feels far more snappier and quicker than the iPhone 5. And previously, I used to plug in every night at 25-30%. Now I am plugging it in every night at 45-50%.