Greetings! Here are my thoughts after completing full run:
...Removed backstab? Bruh. How does a filthy casual like me should play rouges?
There is a way to get Sneak Attack without backstab, you need to have another character putting the enemy in the "threatened" status and within 5ft.
I'm glad backstab is gone because I no longer have to waste time rotating my characters at the end of the turn (to avoid giving the enemy backstab). Not having to deal with the micro-game that was created by backstab being a mechanic has helped speed up the flow of combat tremendously.
