Correct me if i'm wrong, but doesn't Agility only increase crouching speed? What's the point of it if you're not going to use Covert training 2 or 3 then? Might as well just go walking around the map then, because people can see you through listen mode.
It increases crouching speed and walking speed, and the speed with which you climb or vault over things.
And you've missed the part where I say people don't seem to be using listen mode as much as expected.
It's really useful because as you said people are playing more agressively and therefore less cautiously so I have a great time flanking enemies and taking them out 1 by 1. It's also quite nice for stalking someone for a shiv because you can walk faster than them.
I've been testing out Agility and also removed covert as Scoot suggested. Scoot does have a good point that Covert with Agility may not be needed. I'll trail behind and follow the other team and occasionally use listen mode to make sure they aren't covering themselves. Almost all the times, I was able to follow undetected. I've had a lot of games where I flanked and took out 3 guys and once in awhile all 4.
I'm liking Agility not necessarily for the flanking ability, but the fact that in combat you can make an escape and being harder to catch up to. You can easily get away from a lot of battles without running. While running away has it's place, walking away with Agility 2-3 on is better in a lot of cases.
I've noticed that the difference between the walking and crotch walking speeds of Agility 2 and 3 is pretty significant. If you are going to dump 3 points into Agility you might as well put in 4 for the significant increase in speed. Really helps when trying to shiv someone.