Query Builder vs. Oracle/SQL Server views

Hello

I was wondering if anyone cared to share his/her thoughts on using Query Builder vs. Views. I know that QB has the built-in Lawson security but am wondering if reporting performance will suffer as more than a handful of tables are added for Crystal Reports (deployed via LBI). In some cases, the way that the data is stored in different tables (PRSAGDTL, for example) isn't ideal for the way that 'normal' end-users look at it. Using SQL server to create a view in the dB wouldn't by utilize Lawson security, but if the end-users wouldn't be restricted to any records, wouldn't the performance improvement justify the tradeoff? Also, I believe that you can lock down that view to individual users anyway if that was a major issue.

Thanks.

ps