Interesting reviews. However, the entire downside to Blaziken Ex is the negative effect of Burn Away and that's what makes it a bad card IMO. It's always great to do solid damage, but when you have the potential to kill a basic which can Candy into a stage 2 beast to destroy and kill yourself in the process giving 2 prizes to your opponent is too much of a gamble to base a deck around.
Atm in this CURRENT metagame there isn't any solid combos to make it viable for a decent deck. Until a decent combo is found then there's no way it's going to be seen as a good card, or played competitively. Banette ex and Luvdisc aren't "real" combos for Blaziken ex IMO. Luvdisc can go into any deck and Banette ex is just a slow way of removing the counters from the damaged up Blaziken which won't do too well seeing as Banette ex must be active.
I would have given it a 4/10, but because Drag Off is good + it has decent HP i'd give it a 5/10.