Going through bitcoincore.org, you can see that Segwit is included in version 0.13 and we are now at 0.14.2, so Segwit not only is supported by core developers but it is thoroughly tested and already present in all current versions.

It is the activation of segwit that causes all that uncertainty as the activation is user initiated by UASF and has met with opposition by miners, most notably bitmain, who even threat with hard forking.

A smooth, soft fork transition to segwit will significantly strengthen bitcoin and will drive prices much higher.
A hard fork by a significant percentage of hash power will create two coins and a long period of uncertainty.

This uncertainty will quickly drop prices so that the two new bitcoins (the legacy/segwit one and the bitmain/bitcoin) together will have a much less value than the old bitcoin has now.

I believe soft fork segwit will dominate and bitcoin will smoothly continue its course.

Having activated segwit, the scaling / fees issues are NOT resolved but certainly relieved a lot.

This fact, along with opening the road to Lighting in a year or so and other Layer 2 applications, is going to sustain and increase the value of bitcoin and the role it plays as crypto-gold.

Signal for UASF segwit!