I voted No.
Although I've been playing TE4 for a week, I've played TE2013 for almost 10 years, and the service has remained the same, and I'd like it to stay that way, I find it excellent.
I've been playing with the x-box 360 controller for pc for years and have learned to measure strength with simple button presses, whether it's a strong, normal, or safe serve. Any other method would not help me, that's fine by me.
And then with a charging bar it would seem to me like going back to the Top Spin days that I played on Windows in 2008-2009, before switching to Linux, and which I didn't like, it didn't feel like a real simulation here.
Generally speaking then, in tennis games I really don't like having a charging bar for shots, not even possibly for forehand or backhand shots.
One of the many things I like about this wonderful game, is the absence of these bars.