This is a completely non technical post, by the way.
In the last two days I have been busy moving my current project to using NHibernate 1.2 and dropping all references to NHibernate.Generics in favor of NHibernate 1.2's native generics collection. (Finding some horrible business logic inside the Add/Remove delegates that was quite tricky to repreduce reliably).
This project is "mostly read" system, and it feels significantly faster after doing the upgrade. I don't have any numbers, and it may be just a wishful thinking, but I see things responding more quickly.