Good spot to stop over is Thargomindah. Good Motel operator and a nice little town with a good attitude to people travelling through.
As for Marree - you need to understand the politics. Ther Marree Hotel is run by Laurie who is NOT a local, yes he has put in a lot a cabins, but the cost and service is not very good unless you are with a large ground operator who provides most of his business.
The opposition is Lyle who own and runs the Caravan Park/Motel. Again he has put in some 10 new unit, service tends to be better and Lyle has been in Marree for over 30 years so he is counted as a local. Also you need to remember that Lyle also owns the general Store and the fuel in Marree.
Both od these gentleman has a dislike for each other hence what I would call the politics.
If you are going to stay in Marree you should contact Reg Dodd at the Arabunda Resource Centre he does the very best ground tour out to lake Eyre you can get - he takes you to the aboriginal traditional land rather than Level Post bay which is the entry point for ALL the tourist operators.
What ever you decide just remember this town is remote with very limited services and a population this is struggling to keep up with the influx on tourist.
As Lyle has said, all this water is temporary and when it goes no one will give a damm about marree.
Have a good trip and enjoy the spectacular scenery.