Implement SSAS MD cell security using dimension security with blazing performance

SQL Server Analysis Services (SSAS) Multidimensional (MD) is a great product, and in my opinion it's still the only real option to go for when building complex enterprise BI solutions. It's still very fast when implemented correctly and it's mature and therefore very stable.

The only real downside is cell security, which, in my opinion, is useless. It makes performance drop dramatically because it evaluates security cell-by-cell. I have seen reports that run in a few seconds without cell security taking 20 minutes with cell security implemented! Try to explain that to your customer.. It's obvious that you can't.