I don’t think how one could think he or she can sample just one chapter out of a huge book and make a definitive statement about it.
I personally read Susan Epp’s book very thoroughly and read a few chapters in Rosen’s book. When it comes to the difficulty of contents and the amount of discrete mathematics involved, Rosen’s text is way above Epp’s. Epp’s book is very clearly explained but assumes very little from readers. Therefore, it covers very elementary contents.
While I agree that MCS is a great book filled with great content, I highly discourage anyone to use it for a self-study purpose. It doesn’t include any solution. Unless, you already have some mathematical maturity gained from several pure maths courses, the book will not help you much.
Rosen’s text is actually at the sweet spot between Epp’s text and books like Concrete maths. It will serve most of CS students very well. After this course, they can always pick some chapters from books like MCS and benefit from it.