It's funny, and pleasing, to me that we seem to have gone full circle with FPS design since the late 90s.
Back then, the FPS games of the day were all about balls-out speed and mobility. Quake 3, UT, all the mods for Half-Life (sans one important one we'll get to late), had you bouncing around maps like jack rabbits on crack, dodging bullets and rockets and firing back. It was glorious and fun.
Then as we hit the new millenium, slower and more tactical games started to get more popular. Your Rainbow Sixes, Ghost Recons, even Countrer-Strike - which, I know was still fast and twitchy as hell - stapled you to the ground and made you think more about your approach, position and weapon selection than 'run as fast as you can, shoot everything, pick up the best weapon you can find, repeat'.
Then Halo hit on consoles, and set the 'language', for lack of a better term, for FPS design for the next 10 years. Whether in deference to the limitations of the controller input or simply because they wanted to, Bungie set the template for shooters that were a little slower, less vertical, about assessing engagements before you took the first shot, and incentivizing retreat, regrouping and re-engagement when necessary (recharging shields being the big reason).
And now, thanks to Call of Duty:Modern Warfare - fittingly built on the Quake 3 engine for so long - we started climbing right back up to where we started. Faster and faster, less thought, more go, go, go. Titan Fall and now Advanced Warfare brought the mobility back with jet-packs and wall-running and dashing, and it's great.
It feels like home again.