I went to the store all prepared to get a 6+ and then realized just how huge it is... I was going to get 64 Gb 6+ and ended up getting a 128 Gb 6 for a few reasons:
1. I'd need a bag just to carry the 6+. Most female pants don't have large enough pockets to accommodate a 6+ (and then there's bend gate too).
2. I have small hands. I can't even one hand the 6 let alone the 6+
3. There are far more cases available for the 6, some of them great like the pure gear hip case (can be clipped facing inward, outward, the clip doubles as a stand in both portrait and landscape mode, and it even holds a couple cards in the back of the holster. By comparison, the available cases for 6+ there just aren't as many. The pure gear one I mentioned is only available for the 6. I can't imagine a 6+ clipped to someone's belt anyway though... it's just too big.
4. The extra money was better spent on double the storage for music, photos, videos etc.
Size wise, I'd have been most happy if the 6 was 5" vice 4.7" - that would be the perfect size I think, without being TOO big. Though .3" is a a mere difference anyway.
The form factor I love over the 4-5s series. The sharp edges and glassy feel was getting old.
I bought the space grey because black border I find is better for media viewing... and the black REALLY looks great! The screen on this thing, the black is really black, so some of those new wallpapers look awesome (the flower ones with black background). The screen is nearly indistinguishable with the bezel!
iOS8 I am mostly satisfied with too... I gave up my JB for it. They started to include the things I used to JB for like adding widgets to the today summary etc. I can do that now, but the ONLY thing I miss is being able to play with my icons... resize them, choose different icons, make them different colours etc.