I like it and I dislike it.
It gives Fighters an extra (fun) resource to manage in a fight. Plus, as they get the most feats, even as it is available generally, they get the most benefit from having it.
It goes against what I find to be a main draw of the Fighter class: simple. Bear with me here! In my experience, a lot of players are drawn to the fighter precisely because he has few frills and is relatively easy to build and play. I realize a lot of folks on these boards are just the opposite - that's great - but there are those players out there who actually want simplicity. I have one in my game who plays a Fighter.
So, in summary, I don't hail Stamina as the savior of the Fighter. My own Fighter patch does not give out free Stamina because I wanted to leave that as an option for the ambitious (take the Combat Stamina feat) while improving the Fighter in ways that are simple. My fix is to skill points, class skills, good Will save, free Combat Expertise, earlier access to Weapon Training, Armor Training grants DR, and Bonus Feats may be retrained daily. This is basically a list of +1s and +2s, which tend to make sense to the simple player, with the only added wrinkle being retraining bonus feats, which, can also simply be set and not retrained.