We used a macerator pump in our trailer that we built last summer. The front 12 feet of our trailer is a lounge with toilet, sink, and full shower. We have a 60 gallon waste tank and really wanted to keep from having any plumbing hanging under the frame because when we drive into various tracks, it would be easy to get torn off. The macerator pump works well. It takes about 10 minutes to empty the tank and we usually just turn the shower on until the waste pump runs clear.
I finally got a few pictures to upload on here as I used this forum for alot of information. Blizzard had shared ideas on tanks, etc and I stopped over at his shop to visit and look at his truck. We used Sixaflex 252 for any of the seams that didn't have screws. The trailer was alot more work than we originally estiamted, but we used it the last few weeks of the race season and it worked well.