The only time I ever watch the LED, is when I am about to change cards and I want to be sure that everything has been transferred before I open the card door.
I never watch it to judge when I can take pictures again, as you can take pictures at all times apart from just after the buffer is filled. Even then, you only need wait a second or so before you can take another shot or two. It can take some time to stop flashing and you could easily be missing the best shot of the day if you are looking down at the camera waiting for the LED to stop flashing.
If there is action going on (and I presume if you have just filled your buffer, that is quite likely) my camera is to my eye and ready to shoot, or held slightly away, but ready to shoot, if I am looking for where the next good action is likely to be.
I have a fair estimate in my head of remaining buffer space, depending on how much I have been 'bursting', I know that if I have just done several bursts in quick succession that I need to just ease up on the rate of fire slightly for a couple of bursts. I also have the counter in the viewfinder that lets me know when I am down to my last 9 shots or less and just how many I have got.
I think I have only ever actually hit the full buffer three or four times, in about 130,000 shots, in each case I still continued shooting with individual frames as the buffer cleared sufficiently. I have on a number of occasions had to watch my rate of fire as the 'shots remaining' indicator is going up and down like crazy, but NEVER felt the need to stop shooting for 30 seconds or so, to let everything clear the buffer.
I can't see any reason to be staring at a flashing LED, waiting for it to stop, when I could be following the action and getting more shots, any one of which could end up being the best shot of the day. Watching the LED, rather than the action could mean not just missing getting the shot, but also not even realising that it had been there to be got.