Question: Can I get by with the 10th Edition? -- probably not -- however it has useful material and is is better than no book at all.
Question: Can I get by with the 11th Edition? -- yes but the 12th Edition is better.
Answer: You can use the 11th Edition with some risk. Tests are Open Book and I will draw materials for questions from the 12th Edition without going back to the 11th Edition to see if the same material is there. The chapter titles and subtitles are almost identical so the basic material should be very similar. The cases in the 12th Edition are better. They draw on material and examples that are more recent. The authors have picked cases that are very relevant to today's business. I think you will enjoy the reading more if you have the 12th Edition. However, if I already had a copy of the 11th Edition, I would probably use it (I am cheap). You could increase your enjoyment of the course if you borrowed someone else's 12th Edition to read the new cases and the new Management Checklists.
Here is information about what is new in the 12th Edition selected and paraphrased from the preface on the Instructor Review Copy of the 12th Edition:
The 12th Edition contains new opening, closting, and Interactive Session Cases (each chapter)
Management checklists are found throughout the book. They are designed to help future managers make better decisions.
New topics include Cloud computing, cloud based software services and tools, Windows 7 and Mobile Operating Systems, Green computing, 4G networks, Network Neutrality, Identity Management, Search Engine Optimization (SEO), Freemium pricing models in e-commerce, building an e-commerce web site, and security issues for cloud and mobile platforms.