I think any problem I have with rotary cutters is the blade. I would recommend any that automatically closes after you are finished using it. I have some that don't and I find myself laying them down with the blade out, and then let it drop or anything else that puts a nick in the blade. I buy my blades at Harbor Freight. Some people don't like them, but I have had good luck with them. They are so inexpensive that I can change them often and not feel bad that I am using so many. They are used in carpet cutters, so you know they have to be sharp to cut through that.