https://www.youtube.com/watch?v=AlDBxwHqXSI
1) The Shield icon that displays for block should be adjusted to indicate when you're ACTUALLY blocking as it is on Live. The lack of the shield icon specifically on the timeframe when Block is ACTUALLY active after its implementation so long ago has confused many players but otherwise it's shown in the above video
2) Holding block while barswapping feels atrocious. Timeframe for being vulnerable to heavy attacks/channeled abilities is too large and too punishing, probably going to be a nightmare for many especially in PvP and for newer PvE tanks. Barswapping too many times or other factors including getting CC'ed while you're holding Block (while barswapping or whatever) can bug out block to the point you have to RELOG for it to work again. Hopefully will be fixed on PTS.
Lastly, while animation canceling skills with block still work, it feels like some skills are allowed more leeway in terms of how little of their animation is played. This can be both good and bad in my opinion although at the moment it feels very clunky.