3.5 Would this be too much?

[Eldariel]

Imagine, if you will, a fighter with boots that not only allow him to act with haste, but can also act first in each round. This fighter (wielding a greatsword) could deal 4d6+{3*Strength modifier} damage before a single enemy even attacked. He would also be able to avoid spells and mundane attacks 20-40% of the time. That is called broken gaming.

Actually, that would be a "needed buff" in the case of the Fighter. The real issue is that when Cleric of Wizard puts the those boots on and starts abusing it while still not giving up any spell levels, or Dweomerkeeper/Incantatrix access, all hell really starts to break loose. When all creatures start combat dead/incapacitated/mind controlled unless they have the same boots, you know something's wrong.

Though I wonder how you get the "also act first in each round"-part; no PrC to my knowledge grants that directly through a spell, and only few boost Initiative, none through spell effects. But still, e.g. Swiftblade Haste Boots would suddenly give all casters access to 3.0 Haste without lost CL & PrC access, no thanks.