I think the real question to be asking is:
Who would take toughness in 3e? Not me!
5 hp per tier is good, makes the feat balanced. Also the bonus to your surge value is great. Still, I find that most characters don't take it, only some do. This is opposed to 3e when people almost never took toughness.
I'm not sure about the +2 DEF feats. I haven't used them much in play, but considering that most monsters will be attacking your AC, I think they are balanced, and I can see characters not taking them.
I think a feat is imbalanced if everyone who can take it does, or if no one who can take it does. If a portion of the characters (maybe one or two in a party of 5) take a feat it is probably balanced.