I disagree. Itachi was cool because of the Mangekyou - not because of it's power though, but because of the way he used it. He never just straight away used it, he kept it as his secret weapon to surprise enemys.
The way the mangekyou developed after Itachi however is rather sad. Ppl using it constantly rly sucks. What made the mangeyou cool in the first place, was how little we knew of it: only a few uchiha ever awakened the mangeyou. That's it! That's all we used to know! But then Mangeyou keept poping up everywhere up to the point where we see (in a flashback) how Uchiha used to use Izanagi all the time, wich requires Mangekyou, so yeah. Now we know that it's a casual skill and every second Uchiha used to use it. Yup. Sad story.