Hmm, a "great phone" with problems is not a great phone, pal.
Besides, I thought the 6S was a great phone?
This has nothing to do with fear, it has everything to do with having a reliable, bug-free product with the
right features.
Apple usually gets it right the
second time around. Obvious examples of this being:
iPad vs iPad 2

Watch vs

Watch Ver.2
iPhone 6 (bendy!!) vs 6s
Unibody MacBook (original missing FW) vs 13" MBP
iPad Air vs iPad Air 2
I will never, ever (again

) buy a first-gen Apple device.