If your bar is held firmly at “must be build-changing” then no, you’re not going to be amazed by most of these items. (You’d also have hated 98% of the uniques and Runewords in Diablo 2, by that standard.) Most of the RoS legs are equivalent to very good Rares, often with higher values on their bonuses than you can get on Rares of the same item type, and there’s (almost) always that orange text legendary-only bonus, many of which are partly-randomized, and most of which make changes to how you play the game, or at least add a fun flavorful effect to your gameplay.
My Hardcore Monk has essentially permanent triple-stacked Nephalem Glory thanks to the affix on his Gift of Silaria + Blinding Flash. If you watched some of the gameplay on our last podcast you saw that in use, as well as the constant showers of gold courtesy of Neinball’s Gladiator Gauntlets. Another interesting one is the Danetta’s Revenge my Demon Hunter found today. It’s thumbed up above and note the orange bonus and the themed set bonus which could completely change how Vault works for that character. (I don’t know the new orange bonus on Danetta’s Spite. Another something to Vault?)
Click through for the full gallery of 46 new legendary screens. Note that these are all real items that have been found in the Reaper of Souls beta. They’re not just hypothetical items created via datamining, which may yield deceptive values or incomplete stat displays. (Trivia! 1) You can see the possible “roll” on an item by holding the Ctrl key and legendaries often have higher potential values for their stats than Rares of the same item type; 90-100 for res all vs. 70-90, up to 950 on mainstat vs. 750 on rares. Etc. 2) In the Mystic’s Enchant window you can see all available affixes and their potential range, and these ranges often cap out at a number *lower* than what your legendary actually has. This might be a bug, but I think it’s related to point #1; that the roll when a Leg drops is better than the Enchant replacement roll.)