I also use the RCBS case prep center. I have had no problems with what so ever and I have "prepped" a lot of cases. I have a drill powered RCBS trimmer, so I do not need the Lee conversion. If I had zero tools, I would seriously consider the Hornady case prep center. It is more expensive, but does all of the prep work including case trimming and it looks like it is built very well. For now and into the future, I am satisfied with my set up.
Good Luck and Good Shooting