Actually, my meter is very smooth about 90% of the time. It is impossible with the "bad" version of Flash that was extant for a while.
On my system (Windows 7 64-bit Pro), with my clubs and balls, screen size, resolution, and the size of window I use, it still has to lay down a dozen or so pixels (longitudinally) per time slice. I set my window to about 1288 by 915 pixels out of a total screen resolution of 1920 by 1080. I never play it full screen. The smaller the window, the smoother the meter.
On my system, the basic time slice is about 32 milliseconds. As I have mentioned previously, there are some things a system-level programmer can do to get more attention from the system at critical times, at the expense of giving up time when one has no immediate use for it, or at the expense of causing increased power consumption at the cpu.
I have no way of knowing how WGT is actually programming this section of the code. I do know that they're working from a browser through Flash. I, personally, would not have done it in that way.
I do know that the meter operation is on the local machine. One can prove that by setting up a shot, unplugging the modem cable, and taking the shot. The meter will run right up until the ding is hit (or missed) and then wait for information from the servers. Plug the cable back in, off she goes, plotting the trajectory and pulling up the next scene.
This local operation CAN be influenced by connection issues if multiple threads are running at the same time (such as pre-fetching graphics or contour information in the background). It can also be influenced by other applications that are running simultaneously, particularly if they are using a lot of cpu cycles.
What I do is make sure that no other applications are running. I also make sure that no system services are running that want to use the cpu (auto defrag, file cleanup, file indexing, stuff like that). I have also turned off auto updates for both Chrome and Flash. As a matter of fact, NO updates run automatically on my machine, not even Windows updates. I do that manually on Tuesdays every week or two.
My options are set for no background loading, Flash at High (not Best). I allow Flash to store up to 1Mb. My browser clears cache every time it shuts down (but not cookies).
I have personally (and purposefully) set up my system for performance, not looks, although I do allow Aero.
At least once a day I check the Task Manager to see what might be running. Chrome runs at least one thread, plus an additional thread for each tab. It tends to accumulate threads, sometimes not shutting them down even when tabs are closed. I shut it down when I'm not using it, so those go away.
I have a smooth user experience with WGT. That doesn't mean I like everything they do, or the bugs that are extant, or some of their algorithms. I don't. Currently the game offers me more enjoyment than it causes me grief. I'll continue to play it so long as that is the case, and it offers challenges in improvement. Currently I REALLY need to learn to putt better. I'm suffering from "new legend shock."