We were not planning on going into London on this ...

We were not planning on going into London on this trip. However our plans changed and since my wife had not seen the Tower that was our choice.

We paid the money and used the audio guides but of all the place we used it, surprisingly the Tower was the least beneficial. Some of our friends disagreed with this opinion and so your experience may differ.

We looked at the line up for viewing the Crown Jewels and we decided to pass. An hour later, ~45 minutes before closure, the line was more reasonable and so we saw the Crown Jewels. Hence, at least that day, waiting for the end of the day worked well.