It's great to be able to filter portals in the portal setup dialog. I would love to see that same function added to the Go To Related Records script step.
For example, suppose I have a relationship from Customers to Invoices. I can set up a portal to only show invoices over 30 days old by filtering the portal. But if I want to go to those related records via a script (not by clicking on a portal row), I can't filter the relationship. So I either have to create a new relationship and the corresponding fields that would accomplish this, or do it via scripted Find.
How much easier it would be if I could simply GTRR where Invoices::DaysOut > 30, or something like that.