My experience has been the same as bigfootford's. The bytal take does a much better job, especially if you have to use more than one layer. Personally, I will never use the clay type tape again, and will not even consider silicon seal.
I prefer to have the tape stick out at least 1/8" all around the frame. When you tighten the screws, it squeezes out and it is much easier to see that it is sealed all around the frame. I trim around the entire window with a plastic putty knife. This photo gives you an idea as to what can happen if not installed properly.

This photo may help you identify the correct tape.

Wayne