I have used NetIQ GPA and if you are looking for ways to control GPO’s this works well. If you are going to be the only one administering GPO’s then this really isn’t the tool for you.
NetIQ GPA gives you some good reporting tools and also some additional management utilities but it’s best feature is the ability to control who approves the final version of the GPO. THere are actually about 5 or 6 roles that you can assign to admins. The last one actually give the admin the ability to apply the GPO to AD.
Some of the other good features are versioning, reporting and rollback of GPO’s. You should be able to download a fully functional trial and install it in the lab if you have one. I know they recomend putting the database (MS SQL) on a different box but that’s really for an enterprise environment where you have multiple child domains and multiple admins managing GPO’s.
Good luck on your search!