This is one of the better tools for DM's and players alike out there right now when in regards to Pathfinder. As a DM I use this software exclusively. It allows me as a DM to bring in any of the creatures from either of the bestiarys and then apply any type of template, advancement, ghost, undead and so on... not to mention I am able to apply levels of any of the classes from either the core rules or even the Advanced Players Guide.
This software as a tool during the game as a DM is very nice too. It is allows me to open the Tactical Console, which then I can apply any manner of condition, adjustment and or anything else I may need. It also allows me to bring in other NPC's, creatures or characters from other portfolios I have created or from stock portfolios that the developers created. This might not seem like much but when I am running an adventure for my group, I input their characters before the gaame and then during the week I go through the adventure either as I am writing it or reading through it, and then take each NPC, creature and then give it it's own portfoilio labled by the name of the encounter and then as I am running the game. I can inport the encounter to the group (groups charcters) I already have opened on my laptop/netbook. then onc ethe encounter is done I can remove the NPC or creature from the game. Making a little note about the outcome of the encounter
As a player, this is amazing software too. Imagine sitting there thinking up a concept for a character yet you have no true idea how you want to build it fromn idea to reality. While looking at the book gives you some wonderful ideas it does not conceptualize quite as well as does Hero Labs. HL allows you to addd levels from any of the classes from either the Core rules system, the 6 from the APG or even the new play test characters that are out right now such as the Magus and the alternate characters such as the Ninja, Samurai, and Gunslinger, not to mention the Sable Company Marine Archetype too. You can go through and see each feat, special powers/class abilities and the like that you can add or can't even. you can add levels up to 20th level if you want and check out each indivdual thing that your character can have and or can't even the Traits, Feats, Skills, Prestige classes, spell like abilities and practically anything you can think of involving the class/character/race you are currently working on.
Also there is the strongest thing I think about with Hero Labs and that is the Editor, Thed editor allows you as a player/DM or just plain user of this software to open the editor and create custom creations, be it classes, races, creatures, items, magic items, custom gear, Abilities, feats or pretty much anything that the game has that you want in it you can do with this program. Now keep in mind there is a little bit of a learning curve with this editor but there are numerous tutorials out there for that as well as the great Hero Labs community that is more then willing to help if asked nicely.
As you can tell I am fairly passionate about this software and while it can get things wrong occasionally the one thing you have to keep in mind if it does get something wrong and you catch it, PLEASE report this in the bug section on their forums under Pathfiner so it can be corrected and then not get it wrong any longer
This software is developed by humans so they occasionally are not perfect hehe.
Hope I answered your question/s?
