Today's CotD is Reshiram EX from ND...well it makes a nice compliment to your normal Reshiram I guess. Statwise 180 HP is about average for an EX, x2 Weakness to is meh, no Resistance is common, and to Retreat is expensive. Glinting Claw is meh, for a mere base 50+ 30 more if you flip Heads isn't that good. Brave Fire deals some nice big damage though at for 150, but has a 50/50 chance of dealing 50 to yourself as well, which kinda sucks. In terms of the main decks that use him (Reshiboar and TyRam), he offers a big damage attack that allows you to OHKO most opposing Pokemon, so he would replace basically the "bad boar" in Reshiboar decks (since the only reason you ran one was for the big 150 to take out annoying stuff like Goth having damage soaked up by Reuniclus) and offers a big attacker for TyRam (I'm sorry, but I still don't get why the heck people say Typhlosion is a good attacker, it stinks in damage done). So I wouldn't use any more than 1-2 (in case you're worried about 1 being prized), along with your usual 3-4 regular Reshirams for the normal attackers. And eh, even then I'd personally prefer Mewtwo EX in those decks for better coverage and so not everything you run is weak to .
Modified - 7/10 - It's not bad, but Mewtwo EX would still be my first choice for decks that would even consider Reshiram EX, with it being a distant 2nd. Still, it offers a nice big attacks its regular counterpart can't do, allowing it to come out and (hopefully) OHKO that one Pokemon that's blocking your path
Limited - 10/10 - Why not, it'll cost you half your prizes if KOed but it's a huge freaking Basic with big attacks. That or keep it safe in the binder
Unlimited - 1/10 - Eh, not as useful here, it just doesn't offer that much besides being a big beatstick, and there's plenty here that won't hurt themselves or cost you 2 prizes