We're using MUS after using Miquon, Horizon, and Shiller. MUS, hands down, is our favorite. I have two children using MUS: one Alpha, one Gamma.
We start each lesson with a video. Usually the video lesson introduces some mnemonic device or fresh way of looking at a concept that I hadn't thought of. Then we start on the workbook page. Each lesson offers 5-6 pages of workbook practice, plus a test. (The tests are in a separate book.) The workbook pages for each lesson are "lettered" so lesson 26, workbook page 3 would be page 26C. Pages A, B, C, and D are usually review of the lesson. Pages E & F are usually a cumulative review. If my son has mastery of the concept after one workbook page, then the next day we do the last workbook page for that lesson; we skip most of the tests. (Why do I need to test him? I sit across the table from him and know if he has mastery!) Then we move on to a new lesson/concept the next day. If he needs additional review, there are additional workbook pages available on the MUS website.
You're going to find manipulatives in most elementary math curricula. Children at that age often (not always) need concrete representation of abstract ideas to internalize the concepts presented. (Just like counting on your fingers!) It's normal, and it doesn't mean that children become dependent on plastic rods to do math. If that were true, most of us would need popsicle sticks to balance our checkbooks!

We really like MUS. The video lessons are very helpful, the online workbook pages and drill work are valuable, too.
I just asked my 9-year-old why he likes MUS, and he said it's because Mr. Demme is good at explaining, and he has plenty of practice to get it right. He thought that the other programs we used expected him to understand concepts right off the bat.