It's my first post in English here so if I write something wrong, sorry.
The TMG is old and weak, there are many other solutions in activity, not only open Source like the PFSense.
The major problem with Microsoft is the propaganda, they sell you a product like it's the only solution in the entire universe. I'm a Windows user, but Linux/Unix is much more secure.
I'm not here to rise any banner, but if you want to start a conversation about UTM Software, please, use something that have a possibility in combat. The PFSense project have a lot to evolve, but in front of a TMG/ISA...
So, "supermule", demonstrate for us some feature that TMG provides you better than PFSense... Well I'm pretty sure that YOU don't know how to use PFSense and now come here talking nonsense.
AD integration is an advantage, but Squid, Captive Portal, VPN and many other packages on PFSense can do that, with Freeradius2 it's even more easy.
You can't talk about something that you don't really know.
I've tried a lot of systems for border security and I chose PFSense. I tested every solution I come to know and I finally decided on PFSense.
How many experience do you have as a Sysadmin? How many projects do you have implemented with PFSense?
Here in Brasil we say: "Those who talk too much will go say good morning to the horse".