Pros
This is almost the same card as the dark houndoom. I won a professors cup with that card. This one is better. Here's why, 90 hp, no double weakness, basic dark, great supporter and trainer combos in the format, and super good 1 nrg first attack with a superb 2 nrg 2nd attack. This card combos so well with so many cards in this set such as multi, dre, crystal beach, absol, but for me the cards that breaks doom that were not available when dark doom was out are basic dark energy, rosannes, castaway, wager, & scott supporters with crystal beach/cess crystal lock/maintenence trainers. This lock stops the opponent early and lets you find a basic dark to discard, or a cess crystal, or a gym, or pokemon on almost any turn without needing claydol. This basic nrg search is why I did not play multi in my 2nd place regionals deck. I prefer a searchable renewable basic energy comboed with the supporters & trainers above. I did play dre but hardly used them. I hardly ever discard fire. I also played 4 special darks. I had 3 long games (I won them all) and all my other games were 5 turns or less. You survive long games with the supporter/trainer lock.
Cons
The downside is I believe water will big after the next set and with 90 hp doom is a bit fragile. Doom is also hurt by furret. 90 hp is a 2 hit ko for doom. That is why wager is required with doomlock. Doom is no longer a surprise so that hurts too. Gallade can OHKO you for 3 nrg with the lock in place.
At regionals - 10/10 - surprise factor
Now 8/10 strong
After next set 7/10 or maybe 6/10 - water ouch