My wife and I are making very good use of your superb Uganda guidebook. It’s a fantastic resource.
Your writeup of Mabamba was spot on, but it’s worth mentioning that it’s much easier and more convenient to take a speedboat from Entebbe to the swamp than to go by road. Wild Frontiers Safaris http://wildfrontiers.co.ug operates the excursion daily (the other safari companies book in turn with Wild Frontiers).
The boat takes 45-50 minutes each way. When you get to the edge of the swamp you transfer to the canoes with the local guides and go looking for shoebills and other wildlife. When done, you transfer back to the speedboat and return to Entebbe.
The speedboat is covered, in good condition and life jackets and water are provided. It’s a comfortable ride, and it’s nice to see the islands and part of the lakeshore.