OK. Let say you can spend three feats to improve your saves, and you DM lets you take feats several times, even if it isn't normally allowed.
Would you take Iron Will+Lightning Reflexes+Great Fortitude (+2 everywhere, so a net total of +6), or take Luck of Heroes three times (+1 luck bonus, +1 luck bonus, and +1 luck bonus everywhere, so a net total of +3) ?
With IW, LR, and GF, you get a +2 bonus, but a strong +2. A worthy +2. With LoH, you get a +3, but a weak +3. A +3 that'll get surpassed by items, spells, and prestige class abilities.
So it's good, but not that good.