The deck does definitely have a “poster boy” status in the class of '16. It's flashy, can set up blazingly fast and hit for 200 damage on the first turn, while also being immune to Laser and having a build in Lysandre.
However, even back when the holy trinity was Rayeels, Lando + Garb and Genesect, Ray used to tech Victini and Lando had at even 50/50 match-up, depending on the draw even slightly favourable for Lando.
Nowadays the deck is merely a relic of the past, since non-EX attackers have taken over the format, leaving the old guys in the dust.
The reason I'm so hostile against the “Genesect so OP!” statement, is that the majority of those come from players who haven't played Legacy in a long while and thus have a rather distorted image of the meta game.
As for TB:
Unlike Expanded, where you can't run Wailord / M-Groudon without TB ( ok you can do that, but it's a million times worse), every Legacy deck that gets better with TB also works perfectly fine without it.
Though I'd wish they'd be a little cheaper never the less .
The shadows of the abyss are like the petals of a monstrous flower that shall blossom within the skull and expand the mind beyond what any man can bear, but whether it decays under the earth or above on green fields, or out to sea or in the very air, all shall come to revelation, and to revel, in the knowledge of the strangling fruit - and the hand of the sinner shall rejoice, for there is no sin in shadow or in light that the seeds of the dead cannot forgive...