My DW and I stayed at the Sheraton Safari for a professional conference she had at the hotel earlier this month. The rooms are adequate (we later moved to a suite because there were no King beds available) and the grounds are OK. It certainly isn't a Disney property (the second part of our stay we spent at POFQ which was cheaper and better than the Safari).
The biggest hassle with the Safari was the lack of adequate transportation. The shuttle to the DW resorts runs only several times per day, is often late and stops at every hotel (the three days I used it, the 'other' bus driver called in sick resulting in the driver telling passengers that we would have to make a few additional stops).
When we asked the transportation desk for a cab, we ended up paying $20 to go to DTD and still having to make stops out of our way for other passengers.