I mean if the ramp-up for EM in Legion was a problem you always had TfT to make it instant cast. The CD on TfT really isn't that long.
Also REM randomly jumping around can be problematic if I want it to be on a certain target to spot-heal.
There are just a lot of extra boxes to check, and overall we feel less versatile. We could respond to all of the same situations in Legion, and more.
Being able to TfT>EM in Legion was huge and offered a lot of emergency healing potential. The 1 Sec SooM>ENVMist is not the same in BFA. Not to mention it doesn't have the same initial burst heal it had in Legion, unless you waste TfT.
We honestly feel hog-tied to the Global Cooldown now, whereas in Legion you could heal on the go a lot better.
For example if our group got into a sticky place in Legion that came up unexpectedly, I could TfT and double EnvMists two people beginning IMMEDIATELY. Now I have to: Cast SooM > Wait 1 sec > EM > change target > Cast SooM > Wait 1 sec > EM, etc.
It's just slower and clunkier when responding to things. In the majority of situations hard-casting EM/Vivify was fine. But old-TfT let us respond to those emergencies a lot quicker than what we have now.