The echo cost can be a burden unless you can turn discarding a card into a benefit, like with a card like Bloodghast
Boros is traditionally poor from behind, so by all means punish them if they stumble and you have a good curve
But seeing those pieces in person, all of us gazing in awe, is when I knew this set was going to be something special
Yep, they do
If this is news to you, then first thing's first: you should check out our Revitalizing Standard article
Aside from being a human, which is a very relevant creature type in Commander, Modern and basically every other MTG format, Esper Sentinel is good because it reads: Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays X, where X is Esper Sentinels power. Its a bit like Rhystic Study, but the cost can be far higher if youve got things that make humans stronger or you can put +1/+1 counters onto Esper Sentinel