Hi Alan,
I only ever been once high/high season on the Broads, and two days was more than enough up on the Northern rivers. Its a madhouse, and you do need to keep your wits about you.
In saying that, the biggest problem and I should imagine even more now with even less mooring options is, you need to put your cruising hours in early, that gives you half a chance of a half decent mooring.
For those who like to mud plug, then as long as you are well stocked up, and perhaps have a dinghy there is no trouble at all, or shouldn't be.
I am off to watch the Third Test. Have fun!
An example of the busy Wroxham taken recently.
Iain.