I pretty much main Enrage in all of my War decks.

For me, the main appeal of Enrage is the ability to drop Blitz creatures with unexpected threat ranges, setup Blood Rage combos, and spend leftover mana pumping up Armor creatures like Strix Conscript.

This shuts down early Control Magic, for example:

T1: Enduring Shield
T2: Bladecaster + Protect (baits 2-card removal from dummies, else Health ramps)
T3: Strix Conscript + Protect (immune to Magebolt, also requires 2-card removal)
T4: ENRAAAAAAAAAGE that dang Owl! (+1 Strength through the Protect!)

This works whether you go first or second, and it's not even a particularly "specialized" opening, as it's just one option for dealing with "plinker" (1pt of damage) Domains. It even extends to options like Hearts of Bronze, Guild Enforcer and Phalanx Lieutenant. If you're running a Control variant, even Bronze Gate can be Enraged!

My dream Enrage deck combines creature ramp with Armored Creatures for truly "Beefy" monstrosities that have no business ruinin' peoples day. I just need some of the more expensive Genesis/TotG cards, first :P